Bullet In. Of The. It Nit-E D F State S Geological? SurveySTATE S
GEOLOGICAL? SURVEY
7N o ;
IL BRYOZOA.
N ICKLEs '
AND BASSLER .
WA S H IN GTON GO V E R N M E N T P RI N T I N G O F F I C E
1 9 0 0
DEPARTM ENT O F TH E INT ER I O R
B U LLET I N
OF THE
U N I T E D S TA T E S
GEOLOGICAL SURVEY
WA S H IN G T O N
GO VE RNM E N T P R IN T I N G O FF ICE
1 9 0 0
UNITED STATES GEOLOGICAL SURVEY
CHARLES D. WALCOTT , DIRECTOR
‘
WA S H IN GTO N GO VE R NM E N T P R IN T I N G O F F I C E
1 9 0 0
Letter oftransmittal Introduction and acknowledgments Explanatory notes Classification Systematic posi tion History ofclass ification Scheme ofclassification ofPaleozoic bryozoa Term inology Diagnoses ofsuborders, fam i l ies , and genera Alphabetic l ist ofgenera showing systematic posi tion Alphabetic l ist ofinval id generic names
Distribution Geographic Geologic List oflocal ities Table showing th e occurrence ofbryozoa by formations Lists ofspecies
Cincinnati Silurian Devon ian Mississipp ian Carboniferous
Tables ofgenera and Species In th e groups ofth e Trenton period In th e groups ofth e Cincinnati period In th e periods ofPaleozoic tM e
General notes Value ofbryozoa in stratigraphic work Col lection and study Making ofsections
Bibliography and index .
Chronological catalogue ofpapers conta ining descriptions and i l lustrations ofAmerican Paleozoic bryozoa
Chronological catalogue ofpapers conta ining descriptions and i l lustrations of American Mesozoic and Tertiary bryozoa, with l ists of spec ies described there in
Catalogue of th e genera and species of American Paleozoic bryozoa , including bibl iography and synonymy Index ofspecific names .
Index ofau thors and the ir papers List ofpapers treating ofbryozoa Th e foregoing list classified
LETTER OF TRANSM I '
May 21 , 1900.
SIR:I have the honor to submi t herewith , for publ ication as a
bu lletin of the United States Geological Survey , the manuscript Ofa
joint work by Mr. Ray S . B assler and myse lf , entitled A Synops is ofAmerican Fossil Bryozoa, including Bibl iography and Synonymy .
Very respectfu lly , JOHN M . NICKLES.
Hon. CHARLES D. WALCOTT ,
ASYNOPSIS OFAMERICANFOSSIL BRYOZOA.
IN TRODUCT ION AN D ACKN OWLEDGM EN T S .
So voluminous has the l iterature of natural h istory become that the workers in any special branch
, and the general student as well
, fee l the
need ofcomp ilations showing what has been done . This need , keenly
‘
the serv ice ofou r fellow -workers with the hope that it may l ighten the labors of the
systematist and open the way for an enlarged u se of the _
bryozoa in
stratigraphy .
The bryozoa are generally admitted to be one of the most difficu lt groups of fossils . They are often of smal l s ize and can seldom be
determined by the unassisted eye . The ir accurate discrim ination necessitates tedious study . Few have cared to give this . Because , also
, great uncertainty has prevailed as to what constitu tes classifica
tory characters , a large amount of confusion and synonymy cumbers
the l iterature of the sub ject. Thus the study of the bryozoa has become doubly repel lent . The extended investigations of the structure offossil bryozoa made
by Mr. E. O. Ulrich , following in the lines pioneered by Dr. H .
Alleyne Nicholson, have shown that we can not be sure ofthe position ofany form in the scheme
“ of classification until we have learned its
internal structure by means ofth in sections exam ined m icroscop ically .
This mode ofinvestigation is difficu lt and tedious , but ou r studies have
convinced us that a knowledge of internal characters is absolute ly essential to a correct understanding of phylogeny and systematic position.
As but few. authors have described the internal structure of their
spec ies , and as those who have given descriptions have not always had
a clear understanding ofwhat is essential in the appearance presented by th in sections
, it is not poss ible to be sure of the generic placement
ofa large number Of species . Some au thors have referred species to genera to which we are certain they do not be long ; but as enough has not beenmade known ofsuch forms to enable us to refer them toother
9
genera , even doubtfu lly ,
w e have left the spec ies where placed by the ir au thors
, bu t have followed the generic name with two interrogation
points ( 2 We have deemed it best to be conservative in the matter ofreducing
to synonyms , and only where the au thor himse lf or some very good
au thority or ou r own investigation has ju stified such a course have we relegated a spec ies to synonymy . At the same time we fee l sure that fu ture studies will show that a cons iderab le number of spec ies given in our catalogu e as vali d are synonyms Ofspecies previously described .
This is especial ly the case with the bryozoa of the Ham i lton group .
These have been dealt with by a number ofworkers , most ofwhom
have seemed to not concern themse lves very much abou t what others may have been doing .
Some genera which fu ture research may prove to be bryozoan we have excluded . Such are Au lopora, Monilopora , Vermipora, Stri
atopora , M ichelinia, Chaete tes , Favosites , and Tetradium .
The catalogue gives a l ist , complete so far as we know
, of the
described spec ies of bryozoa from American Paleozoic formations ,
arranged alphabetical ly under the ir genera , which are also arranged
alphabe tically for convenient reference . The b ibl iography of each spec ies is given under its caption
, thu s enabling the student to eas ily
trace the history ofany particu lar form in the l iterature . The cita tiOns under the genus nearly always refer to a diagnosis ; i t has seemed to be of no value to record citations which do not contain some sub
stantial contribu tion to the knowledge ofthe genus .
We have not been able to deal with American Mesozoic andTertiary bryozoa in the same manner. Practically nothing has been done with these s ince the work ofGabb and Horn in 1862. B ut not much can be done yet, for the c lassification below the h igher groups ofrecent and post—Paleozoic bryozoa is in a most chaotic condition. This systemati
zation mu st be done by European writers , as America has but a com
paratively feeble representationofpost -Paleozoic bryozoa. The subj ect is difficu lt
, but the researches OfSm itt
, H incks
, and especially
Waters , are lay ing a sure foundation upon which the classification of
the fu ture may be safely bu i lded . As the best that can be done at
present , we have given a l ist of all publications describing American
Mesozoic and Tertiary bryozoa, with the spec ies described in each .
As additional helps to the study ofthe bryozoawe have given a brief ou tline ofthe class ification
, with terminology and diagnoses ofgenera ,
fam il ies , and suborders ; tab les Showing the distribution ofgenera and
species geological ly ; and various notes and hints that we deemed m ight prove acceptable to the student . One feature we have added which seems a little fore ign to our pur
,
as comp le te as we have been able to make it , treating ofbryozoa.
mom s AND BASSLER.] EXPLANATORY NOTES. 11
This l ist will give a very fair idea ofwhat has thu s far been done for the bryozoa. For kindly he lp which has done much to make this l ist as ful l as i t is , we have to thank Dr. Josua Lindahl
, the accomplished
Director ofthe Cinc innati Soc iety OfNatural H istory , andmany work
ers abroad , morc particu larly Prof. Sidney F. Harmer , Mr. Arthur
William Waters , Dr. Ed. Pergens , Prof . H inrich Nitsche , Prof . E.
Ehlers , Prof. F. A. Sm itt
, M . Gustave Dollfus
, and Dr . A. Neviani.
I t remains to acknowledge our very great indebtedness toMr. E. O.
Ulrich , ofwhose lifelong studies ofthe bryozoa ,
publ ished and unpub
, Often under
most untoward c ircumstances , we have been free ly perm itted to avail
ou 1 se lves To the DirectOI of the United States Geological Survey , Hon.
Charles D. Walcott , whose keen apprec iation of all that tends to fur
ther geological andpaleontological sc ience has beenmany times proved ,
we are indebted for many favors .
EX P LANAT ORX’ N OTE S .
I t has seemed adv isable to give a few brief explanatory notes .
1 . In the catalogue ofgenera and spec ies , val id genera and spec ies
are in black - faced type ; an interrogation point following the generic name indicates that i t is not certain that the species be longs to the
genu s under which it is placed ; two interrogation points following the generic name indicate that
, while we have left the spec ies where i t
,
but we do not know where i t does be long. As a ru le , we have excluded
these species from the tables giving the numbers ofspec ies .
2. In giving the geologic formation we have usually adhered to commonly accepted designations
, though this sometimes produces
, fol lowed by
,
group ; when followed by a parenthes is including Black River or Stones River i t denotes the period . Trenton in parentheses means the group . For the Trenton period Clarke and
Schuchert 1 have proposed the name Mohawkian.
After the term Cinc innati (period) we have given the group in parentheses . This we have done because very few authors have given the group from which the ir spec ies were derived . The recog nition Of these groups is comparative ly recent . The Lower Helderberg we have included with the Silurian in our
table Of formations . I t is still an open question towhich age i t more properly be longs , the Devonian or the Silurian .
We have continued to use the name Upper He lderberg , though the
name
“
Ulste i ian lately pi oposed by Cla i ke and Schuchert, may pi ove —h
l Science , new ser. , ,X 1899 , pp.874- 878.
12 AMERICAN FOSSIL BRYOZOA. [BULL 173.
a be tter designation . Prof . James Hall regarded the local ity at the
Falls of the Ohio as of Upper Helderberg age , but we have fol lowed Mr. E. O. U lrich in considering this local ity ofHami lton age .
Fu ture researches may prove that the Upper Helderberg and Hamil ton
, as now commonly understood
, are to some extent synchronou s .
To avoid amb igu ity we have adopted the term M ississippian for the formations underly ing the Coal Measures andoverlying the Devonian, and have used the grouping of these formations given by Wi lliams
and Keyes , with some modifications .
3 . In the diagnoses of suborders , fam ilies
, and genera w e thought
it adv isable to give the number of undescribed species known to u s ,
as it wou ld give a better idea of the number of bryozoa known from American Paleozoic strata. These undescribed spec ies are in the col
lections ofMr. E. O . Ulrich and the authors .
4 . In the list of publications preceding the catalogue ofgeneraand Spec ies w e have placed an asterisk before those which are ofmost importance to the student Of the bryozoa. The dates w e have given do not always agree with those on the title - pages . We have g iven the date of distribu tion in cases where we know this to be different from the date ofpubl ication .
CLASS IF ICATION .
SYS T EMAT IC PO S IT ION .
The earl iest investigators of the bryozoa regarded them as plants ,
but by the beginning of the nineteenth century there was general agreement among naturalists as to the animal nature of these organ isms
, Often so plant - l ike in appearance . For a time their systematic
position remained in doubt , and they were uneasi ly shifted from c lass
to class . In 1830 J . V . Thompson published h is discoveries , OnPoly
zoa , a New Animal Discovered as an Inhab itant of some Zoophites ;
1
whence most B ri tish au thors have applied the name Polyzoa to these organisms
, speedily dignified as a c lass . Almost simu ltaneously C. G.
Ehrenberg 2 separated these organisms as a group of his Phytozoa
Polypi under the name Bryozoa ; which name became current among Continental au thors and seems now gradually superseding Thompson
’ s
name also among B ri tish writers . For a considerable time the B ryo
zoa , with the Brachiopoda and Ascidia
, formed the “subkingdom ”
Mol luscoidea , but the Ascidia have been removed from this assem
blage , and doubts have arisen whether the points of agreement of
bryozoa and brachiopoda are offundamental importance . The deter m ination of the exact affinities of the bryozoa remains a subject for investigations .
1 Zoo] .Research es , No. 5 , pp.89—102 , pls . i—iii .
2 Symboles Physicss , seu Icones e t Descriptiones Animalium Evertebratorum , 1828—1831.
NICKLES AND BASSLER.) CLASSIFICATION . 13
H ISTORY OF CLAS S IF ICAT ION .
The first serious attempt at a classification ofthe bryozoa was made by D
’ Orbigny .
’ s wide acquaintance with recent and
fossi l bryozoa has perhaps been equaled by no subsequ ent writer.
B ut the system he devised was so largely artificial and burdened with so perplex ing a nomenclature that it fai led to gain acceptance . The
labors ofNitsche , Al lman , and Busk have fixed the principal groups .
ToNitsche 2 is due the div ision into the two groups Ectoprocta and
Entoprocta , the latter containing only the two singular genera Pedi
cellina and Loxosoma. Allman 3 formed the orders Phylactolaemata
and Gymnolaemata , the latter including most ofthe bryozoa and all
forms capable of preservation as fossils . Busk’s suborders Chilo stomata
, Cyclostomata, and Ctenostomata ‘L have been general ly
accepted . To these suborders Mr. Ulrich , in added the sub
order Trepostomata , to include
a num
ber of forms which had been general ly regarded as corals ; and Mr.
G. R. Vine , in added the suborder Cryptostomata.
Recently Dr. J . W. Gregory 7 has raised these suborders to the
rank of orders , and for the Chilostomata proposes five suborders
the Stolonata , with the fam ilies ZEteidae
, Eucratiidae
, and Chlidoniidae
the Cellularina, with the fam i lies Cellulariidae , B icellariidae , Episto miidae
, Catenicellidae , and B ifaxarndae ; the Athyriata , with the fami lies Farciminariidae
, Flustridae
poridae, Steganoporellidae, and Cellariidae ; the Schizothyriata, with famil ies Schizoporellidae , Adeonellidae , and Microporellidae ; and the Holothyriata, with the fam i lies Lepraliidae , Celleporidae , and Smit tiidae. For the Cyclostomata he proposes three suborders:the Articu
lata , with one family ,
the Crisiidse ; the Tubu lata, wi th the fam ilies Tubu l iporidae
, Entalophoridae, Idmoneidae , Hor
neridae , Fascigeridae ,
Osculiporidae , and Theonoidae ; and the Dactylethrata, with the fam i l ies Clausidae and Reticuliporidae.
Zitte l , in h is excel lent Handbuch der Palaeontologic (Le ipzig , 1880)
utilizing the labors ofNitsche , Al lman
, ,
, gave probably as good a classification as cou ld be
given at that time . We have followed in the main the classification in the Engl ish edition ofZittel’s Textbook ofPalaeontology (Macmil
lan Co.
, the section of this edition re lating to the
bryozoa was rev ised and in large part rewritten by Mr. E. O . Ulrich .
Departures from this classification are basedmainlyupon later, hitherto unpubl ished
, studies Of this au thor.
1 Pa] .Franc . Terr.Crétacé , V, 1850—1.
2Zeitsch rift fiir wi ssensch aftlich e Zoologi e ,XX , 1869.
3Monograph ofth e Freshwater Polyzoa , 1856 , p. 10.
4 B ritish Museum Catalogue ofMarine Polyzoa, 1852.
5 Jour. Cincinnati Soc .Nat.Hist ,V, p. 151.
6 Rept. B rit.Assoc .Adv. Sci . , p. 196 .
7Trans. 20 0 1. Soc .London ,XIII, 1893 , and B ritish Museum Cata logue ofJurassic B ryozoa , 1896 .
14 AMERICAN FOSSIL BRYOZOA . [BULL 173.
While there is general agreement as to the suborders and h igher groups
, confus ion re igns in the arrangement of the genera into fami
lies , moI e espec ially ofthe post -Paleozoic fo1ms . This is due in la1ge
measu i e to the fact that the importance of the vai Ions structuI al fea
tures is veiy difie1 ently rated . For *me1 ly most write 1 s conside i ed
zoarial features of chiefest importance fo1 fami ly and gene1 ic group ings
, but of late there has come substantial agreement that zooec ial
features far ou twe igh zoarial characters for classificatory purposes .
B ut as to the relative importance of the various zooecial characters there is no agreement. A great deal of study is still requ ired , espe cially to determ ine the re lationship ofPaleozoic to later forms
, before
the princ iples of classification applicable to this c lass shall be so we l l establ ished that a classification can be made which will be correct phy logenetically .
OUT LIN E OF CLAS S IFICAT ION .
The subordination ofthe larger group ings of the bryozoa shown in the tabular form fol lowing: Subkingdom MOLLUSCOIDEA.
Class B RYOZOA Ehrenberg .
Suborder I I . CYCLOSTOMATA Bu sk .
Suborder I I I . TREPOSTOMATA U lrich .
Suborder IV. CRYPTOSTOMATA Vine .
Group ENTOPROCTA Nitsche .
Order PEDICELLINEA Hincks .
SCHEME OF CLASSIFICATIONOF PALEOZOIC BRYOZOA.
Subkingdom MOLLUSCO IDEA.
C la s s B R Y O Z O A E h r e n b e r g .
Group ECTOPROCTANitsche .
Ascodictyon Nicholson and Etheridge , Jun.
, Vinella U lrich .
Fam i ly B atostome llidaaUlrich .
,
TrematellaHall , Eridotrypa Ulrich , Stenopora Lonsdale , Anisotrypa
Ulrich , Lioclema U lrich , Lioc leme lla Foerste , 2Thallostigma Hal l.
Fami ly Conste llariidae Ulrich .
Constellaria Dana , Stellipora Hall
Trematopora Hal l , B atostoma U lrich
, Hem iphragma Ulrich , Stroma
Fam i ly Calloporidze Ulrich .
Callopora Hal l (emend . U lrich) , 2 Calloporella Ulrich .
Suborder CRYPTOSTOMATA Vine .
, Hemitrypa Ph illips,
pora Hal l , Fenestralia Prout
, Thamniscus King
, Ptiloporina
Hall.
Pinnatopora Vine , Acanthocladia King , Septopora Prou t , Synocladia King
, PtiloporaMcCoy ,
Sphrag iopora Ulrich .
Family Arthrostylidae Ulrich .
Arthrostylus U lrich , Helopora Hall , Arthroclema B i ll ings , Sceptro pora Ulrich , Nematopora Ulrich .
Fam ily Rhabdomesontidae V ine .
Rhombopora M eek , Rhabdomeson Young and Young
, Coeloconus
, Orthopora Hall , Acanthoc lema Hall , Nema
taxis Hall , 2 Tropidopora Hal l, 2Streblotrypa Ulrich , 2Hyphasmo
pora Etheridge , Jun.
Family Ptilodictyonidae Ulrich .
, Clathropora Hall , Phaeno
Family Stictoporellidae .
, Coscinclla
, Heliotrypa Ulrich .
Family Rhinidictyonidae Ulrich .
Rhinidictya U lrich , Eurydictya Ulrich , Pachydictya Ulrich , Phy llo dictya Ulrich , Euspilopora Ulrich , Dicranopora Ulrich , Goniotrypa Ulrich
, Trigonodictva Ulrich .
, Semiopora Hall , Ptilocella Simpson
, Cerame lla Hal l , Evactinopora
Meek andWorthen , 2Goniocladia Etheridge
pora Ulrich .
, StictotrypaUlrich .
Paleschara Hal l .
ZOARIUM (polyzoarium , ccenoecium) . —The composi te structure
formed by repeated gemmation. The form which resu lts is very vari able
, though usually fairly constantfor each Species . Gemmation in a
plane produces unilaminar sheets which are often p arasitic (incrust ing) upon other organisms
, but are sometimes free ; in the latter case
the protecting covering on the under s ide is the ep itheca. Hol low branches lined with an epitheca are a special form of this mode of
Bul l . 173
18 AMERICAN FOSSIL BRYOZOA . (BULL. 173.
gemmat1on. Two uni lam inar sheets growing erect , back to back
, form
a l ilani inar or bifoliate expansion orfrond. The epithecae ofthe two layers of zooecia thus brought together form a mesotheca, (mesial or medial lam inae ) . The smal l pores seen in the mesotheca
, or between
the walls of adjoining zooecia of certain species when thin sections of wel l - preserved spec imens are exam ined under the m icroscope
, have
rece ived the name median tubu li (Ulrich) When gemmation takes places on any side of the zooec ium
, massy
, globu lar
, or discoidal in
shape . Gemmation - in a particu lar direction will produce ramose or
dendroid forms .
Among the Feneste ll idae and re lated fam ilies a network is formed .
The Openings in the network are fenestru les ; bars connecting the
branches are dissepiments. The surface upon which the zooecia open is the obverse, the other the reverse.
MONTICULES and MACUL2E. — It is qu ite common
, especially in the
Trepostomata , for some c lu sters of zooec ia to outstrip the surround
ing zooecia in growth and tower above them. The rounded e levations thu s formed are termed mon ticu les . Sometimes the clu sters consist of mesopores instead of zooec ia, surrounded by a zone of larger zooec ia.
In the latter case the clu sters ofmesopores may not be e levated above the general level
, bu t may be even depressed be low it. Such c lusters
are cal led macu lce .
ZO ( ECIUM (cel l) .— The cav ity with its bounding wall inhabited by the animal . The wal l is constructed oflam inated tissue . In particu
larly well - preserved specimens , thin sections reveal very smal l tubu
lar passages penetrating the walls of adjoining zooecia. To these U lrich has appl ied the term communicationpores .
In some forms , especially among the Trepostomata
, the zooec ia have
the form of elongated t'ubes , which are crossed by partitions termed
diaphragm . The opening upon the surface of the zooecium or ofthe
vestibu le among the Cryptostomata is the ap erture. It is Often c losed by a zocecial cover (closure or opercu lum) . One side of the zooecial cavity in some of the Trepostomata is lined with a series of superimposed vesic les
, the cystip/Lragms (cystoid dia
phragms) ; the ir purpose or use is unknown.
Among the Cryptostomata plates frequently proj ect from the walls into the cav ity ; that upon the posterior wal l of the zooec ium is the
sup erior liemisep tum (Ulrich) , that upon the anterior wal l is the infe rior hemiseptum . The Opening ofthe zooecium among the Cryptosto mata is the orifice; the tubular shaft which is left above the orifice as
the surface ofthe zoarium is thickened by strengthening .or protective tissue in the vestibule.
INTERSPACE . — The part of the surface oft he zoarium between the
apertures of the zooec ia.
nrcxm s w n BAssLER -l DIAGNOSES OF GENERA . 19
MESOPORES (interstitial cells) .— Tubular structures found between the zooec ia ; they are commonly angular or irregu lar in outline in
cross section.
ACANTHOPORES (spiniform corallites , spiniform tubu l i) .— Smal l cylindrical tubes usually situated at the angles of junction of adjoin ing zooec ia,
forming Spine - l ike proj ections upon the surface .
VESICULAR TISSUE . —In a number of forms the space between the
zooecia is occupied by tissue composed of irregu larly superimposed vesicles . This probably served to give strength to the zoarium and
to protect the zooecia.
Class BRYOZOA Ehrenberg .
O r d e r GY M N O LZEM AT A A l lm a n .
Suborder CTENOSTOMATA Busk.
Zooecia usually isolated and developed by budding from the inter nodes ofa distinct tubu lar stolon or stem . Orifice term inal
, with an
opercu lum of setae. Zoarium horny or membranaceous . Marsup ia wanting.
Family RHOPALONARIIDE .
Fusiform segments (2 stolons constricted fusiformly) arranged in a
more or less pinnate manner, impressed or almost embedded in the
host . Zooecia unknown.
Range , Ordovician— ‘
Devonian. A species very similar to the geno type occurs in the Clinton, and another undescribed Species is found in the Hami lton.
Family ASCODICTYONIDIE Ulrich .
Zoarium paras itic , of threada like ramify ing stolons
, wi th bu lbous
enlargements , arranged irregu larly or in stel liform clusters ; surface
minutely punctate . Zooecia unknown.
Devonian. Two described species ; also several undescribed species from the Chester group .
VINELLA Ulrich .
thread - like , tubu lar stolons
, arranged more or less distinctly in a radial
manner. Surface Of stolons sometimes faintly lined longitudinal ly and with a row ofw ide ly separated small pores along the top. Zooecia unknown.
20 AMERICAN FOSSIL BRYOZOA . (BULL . 173.
Genotype:Vinella rep ens U lrich . Three described and five new
Spec ies , ranging from Ordovician toM ississippian.
Suborder CYCLOSTOMATA Busk.
Zooec ia s imple , tubu lar; walls thin, minute ly porous ; apertures
plain , inopercu late
strengthening tissue ; marsupia and appendicu lar organs wanting °
ooec ium a large modified cel l or an inflation ofthe zoarial surface .
Family DIASTOPORIDZE Busk (emend. Ulrich) .
Zoarium adnate or erect , the latter unilaminate
, bilaminate
, or form
ing hollowstems ; zooec ia generally tubu lar ; apertures salient , usually narrower than the width of the zooecium
, never clustered ; interstitial
cel ls wanting ; ovicells mere infiations ofthe surface , with one or more openings .
STOMATOFORA Bronn (ALECTO Lamouroux , not Leach) .
Zoarium adnate , branching dichotomously ; zooecia subtubular
“ or
subpyriform , arranged typically in a single l inear series ; apertures
subterm inal . Genotype:Stomatopora dicitotoma Lamouroux . Range
, Ordovi
c ian—Devonian ; Jurass ic—Recent. Nine described and eight new
Paleozoic species , mostly from the Ordovic ian.
PROB OSCINAAudou in.
tubu lar ; apertures subterm inal . Genotype:Proboscina boryiAudou in . Range
, Ordovician—Devonian ;
Jurassic—Recent. Five described and two new species in American Paleozoic strata
, .mostly Ordov ician.
,
, DIASTOPORELLA V ine) .
, discoid
, flabellate
Genotype:B erenicea di luviana Lamouroux . Range , Ordovician
Silurian , Jurassic—Recent . Six described and several new species in
American Paleozoic strata , mainly Ordov ician.
DIASTOPORINA U lrich .
, immersed ; aper
tures subc ircu lar, not prominent ; zoarial surface between apertures fine ly puncto- striate .
Genotype and only known species:Diastopor ina flabellata Ulrich .
Ordovician.
NICKLES AND BASSLERJ DIAGNOSES OF GENERA . 21
The systematic position ofthe fol lowing gene ra, placed prov isionally in this family , is uncertain.
HEDERELLA Hal l (NICHOLSONIA Davis)
Zoarium adnate , consisting ofa tubu lar axis
, from which the zooecia
,
Genotype:Alecto canadensis Nicholson. Devonian. Six species .
HERNODIA Hal l .
, annulated
equaling in width the diameter ofthe zooecia.
Genotype andonly known species:Hernodia li umifusa Hall . Devo nian.
REPTARIA Rolle (PTILIONELLA Hall) .
Zoarium adnate , consisting of cy lindrical , annu lated zooec ia in con
tact but not coalesc ing along their sides , and proceeding in the plane
of their host laterally ou tward from a median l ine and then upward '
apertures terminal , equaling in width the diameter ofthe zooecia.
Genotype:Rep taria stolonif ’
Family IDMONEIDE Busk .
Zoarium of free or adnate subcy lindrical or subprismatic branches zooecial apertures rounded
, more or less elevated
, usual ly arranged in
transverse rows on two faces of branches , these two faces sometimes
being confluent ; dorsal surface ofbrancheswithou t zooecia ; small tubu lar pores may open on either surface of the branches
, but more fre
Zoarium ramose , solid ; cellul iferous on one face ; apertures arranged
in rows , alternately arranged , ascending obl iquely from the m iddle to
’
, cellu liferous on
one face only ; zooecia subtubular, with prominent, circu lar apertures arranged in intersecting diagonal series ; on both faces small pores irregularly distributed .
Genotype and only known spec ies:Protocrisina ewigua Ulrich .
Ordovician.
, subcy lindrical , with rounded and
more or less prom inently exserted zomcial apertures opening on all s ides ofthe branches .
M ITOCLEMA U lrich .
Zoarl um ramose , cyl indrical , consisting of long tubu lar zooecia
which. are thin- walled and prismatic in the axial region , diverge gradu
ally from the center , and bend abruptly outward near the s u rface
Often becom ing free and much exserted ; apertures terminal , circu lar, u sually arranged in regu lar transverse or subsp iral series .
Genotype:Jlfi toclema cinctosum U lrich . Ordovician. Two de
scribed and one new spec ies .
CLONOFORA Hall .
Zoarium ramose ; branches cy l indrical , consisting of e longate tubu lar zooec ia
, cohering for part of the ir length ,
'
then bending outward and becom ing free ; apertures terminal , not contracted
, arranged in
Genotype:Olm ora seni iredu cta Hall . Devonian. Three spec ies.
DIPLOCLEMA Ulrich .
Zoarium dendroid , branches slightly compressed , spreading in the
same plane ; zooec ia tubular, diverging from a wavy mesial mesotheca ;
apertures circu lar; prominent . Genotype:Dip loclema trentonense Ulrich . Ordovician
, Silurian.
CYSTOFORA Hall .
Zoarium cy l indrical , consisting oftubu lar, ampu llate zomcia , coher
ing for the greater part of the ir length ; distal ly the zooecia bend out ward
, becom ing free and much contracted ; apertures terminal .
Genotype and only known spec ies:Oystopora genicu lata Hall . Devonian .
Family PHACELOPORIDE Ulrich .
PHACELOFORA U lrich .
Zoarium articu lated ; zooecia conical , two or more aggregated to form cone - shaped bundles ; apertures subterminal
, c ircu lar, and
, P/iacelopora p ertenuis
Ulrich . Ordov ician . One new species in the Clinton group.
CCELOCLEMA Ulrich .
Zoarl um form ing hollow branches , lined internally with a striated
epitheca ; zooec ia as in Ceramoporella , but with th icker walls .
Genotype:Diamesopora vaup eli Ulrich: Oerani opora alternata
James . Ordovic ian. Four described and three new species .
ANOLOTICH IA Ulrich .
Zoarium ramose , digitate
long , subpolygonal , intersected by remote diaphragms ; lunarium ele
vated at the surface , traversed by two to six minu te
, vertical
scribed and three new spec ies .
CERAMOPHYLLA U lrich .
Zoarium erect , bifoliate
back ; in other respects l ike Ceramoporella and Cceloclema.
Genotype and only known species:Ceramophylla frondosa Ulrich .
Ordov ic ian B YTHOTRYPA Ulrich .
Zoarium massive or lame llate ; zooec ial tubes long, intersected by thin diaphragms ; apertures subovate
, nearlv direct , lunarium l arge
,
, forming inter
Genotype:Fistu lipora lazcata Ulrich . Ordov ician . Two spec ies .
SCENELLOFORA Ulrich .
Zoarium Simple , peduncu late under surface epithecated; upper sur
face slightly concave and cel lu liferous ; zooec ial apertures occupy the summits oflow ridges radiating from the center.
Genotype and only known spec ies:Scenellopora radiata Ulrich .
Ordovician .
SFATIOPORA Ulrich .
Zoarium form ing thin cru sts , usually on Orthoceras ; zooecia very
short , nearly direct ; apertures irregu lar
, with blunt spines at the
angles , no lunarium deve loped ; elevated , e longated maculae u sually a
conspicuou s feature .
Genoty pe:Spatiopora asp era Ulrich . Ordovician. Ten described and seven new species .
Family FISTULIPORIDE Ulrich .
, Showing on the surface at
irregu lar intervals macu lae or monticu les composed ofclusters ofvesi
Ni c Es AND BASSLER.] DIAGNOSES OF GENERA . 25
cles and ofzooecia sl ightly larger than the average ; lunarium generally wel l developed , sometimes wanting ; zooecial tubes cyl indrical or some
what compressed , thin- walled , with diaphragms ; walls minu te ly porous
apertures usually direct, c losed at times by perforated covers ; ves ic u lar tissue occupies the interzocecial space .
FISTULIFORA McCoy (LICHENALIA Hall , in part
, DIDYMOPORA U lrich
RELLA Simpson) .
, paras itic or free ; under surface
with a wrinkled ep itheca ; zooecia cyl indrical or som ewhat compressed ,
direct or almost so , th in-walled until near the surface
, and provided
usually with a few diaphragms , and encircled by one or more series of
vesicles ; apertures subradially arranged abou t the macu lae , ovoid
, sub
triangu lar or pyriform , the lunarium more or less strongly deve loped ;
surface between apertures smooth or granu lar .
Genotype:Fistu lipora minor McCoy Calamopora incrustans Phil lips . Range
, Silurian—Carboniferous . Sixty - two described and a
considerable number ofnew species .
CYCLOTRYPA Ulrich .
Like Fistulipora, but the lunarium obsolete and the zooec ial tubes circu lar in cross section.
Genotype:Fistulipora communis U lrich . Devonian . Two spec ies .
Fu ture work may disclose new species and Show that species now
referred elsewhere belong here .
ERIDOFORA Ulrich (PILEOTRYPA Hall) .
Zoarium a thin , paras itic sheet ; apertures Obliqu e , subtriangu lar or
ovoid ; lunarium very prominent, overarching .
Genotype:EridoporamacrostomaUlrich . Devonian , M ississ ippian.
Four species described and several awaiting description.
HEXAGONELLA Waagen andWentze l .
Zoarium as in Fistulipora, but the surface is marked off into gener ally hexagonal spaces , which are divided from each other by more or less e levated ridges
, and usually have a macu la in the center of the
inclosed space .
Carboniferous ofIndia. Two undescribed species from the Ham ilton andWarsaw.
PINACOTRYFAUlrich (FISTULIFORINA Simpson, FISTULICELLA Simpson) .
Zoarium usually a thin contorted expansion , with awrink led epitheca
on the basal surface ; zooecia thin- walled , with a few diaphragms ;
26 AMERICAN FOSSIL BRYOZOA .
interspaces wide , occupied by a single series of large angular meso
pores with numerous diaphragms and never presenting the appearance ofvesicu lar tissue ; apertures subc ircu lar , with a well - deve loped gran ose peristome
, but no lunarium .
CH ILOTRYPA Ulrich .
narrow , irregu larly contracting and
expanding axial tube ; diaphragms few or absent ; apertures e l l iptical ,
Obliqu e , the lower margin thickened and e levated ; interstitial ves icles commonly filled by a dense calcareous deposi t near the surface .
Genotype:O/zi lotrypa li isp ida Ulrich . Range , Silurian—M ississip
pian . Eight described and five new spec ies .
STROTOPORA Ulrich .
the surface presents distribu ted among the apertures large , abruptly
Spreading ce lls (regarded as broken ovicells) ; when perfectly preserved these appear as strongly convex elevations with a smal l opening on one side .
Genotype:S trotopora foveolata Ul rich . Devon ian , M iss iss ippian.
Three specie s .
IVIEEKOPORA U lrich .
fle ‘
Xuou s ; zooec ia tubu lar, proceeding in a gentle curve from the meso
theca and opening somewhat obl iqu ely upon the surface and provided with numerou s
, often recurved
, diaphragms ; apertures obl ique , all
pointing distally ; lunarium , when present
, not very prom inent ; rather
large ovicells deve loped , showing at the surface as a convex space with
a small apical opening .
LICHENOTRYPA Ulrich .
Zoarium thin , incrusting ; . in its first stages like Fistulipora ; as i t
matures , large spines and thin walls are thrown up abou t the aper
tures ; numerous subangular ves icu lar openings interspersed among the apertures and scarcely distingu ishable from them .
Genotype and only known spec ies:Lichenotrypa cavernosa Ulrich Lichenalia longisp ina Hall . Devonian.
B USKOPORA Ulrich (ODONTOTRYPA Hall) .
Like Fistu lipora , bu t lunarium remarkably deve loped , proj ecting as
a strong , bidenticu late process nearly half way across the aperture .
Genotype:Eu -slcopora dentata Ulrich . Devonian. Four species.
m u gs AND BASSLEIL ] DIAGNOSES OF GENERA . 27
GLOSSOTRYPA Hall .
Zoarium tubu lar, cyl indrical , hol low ; diame ter oftube 2 mm . ; thickness ofzoa
rium mm . Cel ls tubular, w ith frequent narrow projections (sem idiaph ragms ) from the cel l wal ls extending partial ly across the tube ; two pseudosepta0 11 one side ; cel l apertures pal i form , very closely disposed , frequently in diagonally intersecting rows, th e surface presenting a reticu lated appearance ; apertures w ith denticu lated lunarium ; interapertural space elevate d , form ing ridges ; frequently a prom inent node at th e intersection ofthe ridges, sometimes a depress ion or p it ; surface with monticu les which are lateral ly in contact, giving to the frond an annu lated appear ance ; interce l lu lar space vesicu lose .
1
We interpret the foregoing description to mean that the genu s is like B uskopora , save that the lunarium is developed interruptedly in the zooecial tubes .
Genotype and only known spec ies:Lickenalia p aliform is Hall . Devonian.
SELENOFORA Hall .
Zoarium incrusting ; surface with circu lar maculae surrounded by large apertures ; zooecia tubular, obl ique , surrounded by vesicu lar tis sue ; apertures subc ircu lar, with overarching lunarium and situated in polygonal , vestibu lar areas formed by coalesc ing ridges travers ing the interspaces.
Genotype:Lichenalia circincta Hall . Devonian. Two spec ies .
FAVICELLA Hal l (FISTULIPORIDRA Simpson) .
Zoarium lamellate , free or incrusting ; surface with monticu les sur
rounded by slightly larger apertures ; zocecia tubu lar , cy l indrical , at first prostrate and thin-walled
, then bending rather abruptly and pro
ceeding almost direct to the surface , surrounded by regu larly super
posed vesicles hav ing the appearance of tabu lated mesopores ; aper tures c ircu lar
, with equally e levated peristome
, but no lunarium
,
si tuated in polygonal vestibu lar areas formed by coalesc ing angu lar ridges traversing the interspaces ; vestibu lar area surrounding the aper tures occupied by m inu te angu lar pits .
Genotype:TIzallostigma inclusa Hall . Devonian. Two spec ies .
COELOCAUL IS Hall . Zoarium ramose , hol low ,
inner surface a thin ep itheca with transverse wrinkles ,
and fine longitudinal striations ; ce lls tubular, arising from the ep i theca and paral le l with it for a short distance , then turn ing abruptly outward ; apertures circu lar or oval , sometim es irregularly disposed , at other times in a more or less regular qu in cunx order ; peristomes thin
, distinctly and equal ly e levated
, usual ly smooth
,
but sometimes with numerous nodes or sp inu les ; interce l lu lar space occup ied by irregularly disposed vesicles, or by regularly superimposed ves icles, resembling tabu late mesopores ; interapertural space occup ied by m inute angular p its .
2
spec ies .
1 Simpson , Fourteenth Ann . Rep. Sta te Geolog ist New York for th e year 1894 , p. 562.
2 Ibid . , p. 554.
Family BOTRYLLOPORIDE .
'
vesicles ;
su rface marked by ridges radiating from the depressed center and
increasing in number by b ifurcation toward the margin ; zooecial tubes occupy ing the ridges
, traversed by occasional diaphragms ; depressed
space between ridges occupied by vesic les , presenting a sol id inter space ; apertures in two rows on the ridges
, c ircu lar or oval , with no
lunarium .
Devonian.
Suborder TREPOSTOMATAUlrich.
Zooec ia prismatic or cyl indrical , coherent tubes c learly separable into two regions
, an ax ial or immature
, in which the diaphragms are
remote and the walls th in and prismatic , and a thickened peripheral or
mature , in which the walls are thickened and otherwise changed
, dia
phragms are more abundant , and accessory features, such as mesopores
and acanthopores , are often deve loped ; zooec ial covers , with a smal l central orifice
, present at times
, though probably not deve loped in all
the fam il ies ; monticu les or macu lae a characteristic feature of the
surface .
Family MONTICULIPORIDE Nicholson (emend. Ulrich ) .
Zoarium variable ; zooec ia with cystiphragms in the mature region always ; apertures polygonal , rounded or irregu larly petaloid ; 1116 80 “
pores general ly present , angu lar , with numerous diaphragms ; acan
thopores abundant, usually small .
, incru sting or free ; monticu les
usually present ; zooec ia prismatic , usually thin- walled
, with cysti
phragms both in matu re and immature regions ; apertures polygonal mesopores few or wanting ; acanthopores small
, generally numerous .
Genotype:Mon tic ulipora mamm ulataD’Orbigny . Ordov ic ian , 2De
vonian . Sixteen described and s ixteen new specIes .
ATACTOPORELLA U lrich .
Zoarium generally incrusting, sometimes lobate or subramose ; zooec ia with very thin, inflected wal ls ; apertures Irregu larly petaloid °
mesopores numerous , frequently isolating the zooecia, large ly filled by
a secondary depos it ; acanthopores very numerous .
Genotype:Atactoporella typ icalis Ulrich . Ordovician. Eleven described and three new spec ies .
mos w n BAssw nJ DIAGNOSES OF GENERA . 29
PERONOPORA Nicholson .
Zoarium bifoliate , through branching of the fronds often forming convoluted masses ; surface smooth , usual ly with maculee ; zooec ia with rather thick walls , ring - like in transverse section
, not inflected by the
Genotype:Montic ul iporafrondosaNicholson (notD ’Orbigny): Clue
tetes decip iens Rominger. Ordov ic ian. Two described and two new
spec ies .
HOMOTRYPELLA Ulri ch .
Zoarium irregu larly ramose or lam inar ; surface smooth , with smal l
macu lae ; zooec ia rather thin-wal led , cystiphragms u sually confined to
the earl ier part of the mature region and never present in the ax ial region ; apertures subc ircu lar
, sometimes faintly petaloid ; mesopores
abundant , more or less complete ly separating the zooec ia ; acanthopores
numerous .
Eight described and five new species .
HOMOTRYPA Ulrich .
'
finely crenu lated wal ls and remote diaphragms in imma
ture region and cystiphragms , isolated or in series
, confined tomature
region ; mesopores few , in clu sters ; acanthopores general ly deve loped.
Genotype:Homotrypa curvataUlrich . Ordovic ian , Silurian. Eight
een described and thirty new species .
PRASOPORA Nicholson and Etheridge , Jun.
Zoarium inassy , u sually free , with wrinkled epitheca on the under surface ; zooecia prismaticor cy l indrical , thin -walled
, with cystiphragms
and general ly surrounded by angu lar mesopores ; acanthopores some
times present , but rarely numerou s or strong ; diaphragms crowded
in mesopores .
vician. Fourteen described and six new species.
ASFIDOFORA U lrich .
, according to
age , Offrom one tomany subequal parts , each gently convex , with the
zooecia diminishing in size from center tomargin ; diaphragms wanting ; cystiphragms few in the zooecia ; mesopores numerous
, with close dia
, Silurian. Eight
MESOTRYPA U lrich .
, generally free , with an
epitheca on the under surface ; zooecia prismatic or cy l indrical , with obl ique and sometimes funne l - shaped diaphragms
, which are probably
modified cystiphragms ; zooecia more or less. separated by angu lar mesopores , which become smaller with age , and are intersected by numerous diaphragms ; acanthopores generally present, sometimes of large size .
Genotype:Dip lotryp a i/nfida U lrich . Ordovic ian , Silurian. Ten
described and seven new speci es .
Family AMPLEXOPORIDJE Ulrich .
Zoarium u sually ramose or discoidal , rare ly bifoliate ; zooecia simple ,
prismatic tubes , with a wel l -marked div isional line (seen in tangential
sections as a fine black l ine) between adjoining tubes ; diaphragms present ; mesopores practical ly absent
, but small abortive ce lls some
times occur among the larger ones in the monticu les ; acanthopores
generally abundant , but may be wanting .
AMFLEXOPORA U lrich .
prismatic , with dia
scribed and four new spec ies .
MONOTRYPELLA U lrich .
pores .
Genotype:Monotryp ella aequa lis U lrich . Range , Ordovic ian—De
vonian. Nine spec ies .
Zoarium bifoliate , of irregu lar compressed branches or simple
fronds ; zooec ia prismatic , aris ing from a strongly flexuous mesotheca ;
apertures subcircu lar or polygonal ; mesopore- like interspaces that do not differ in the ir tabu lation from the zooec iamay occur ; very smal l acanthopores ( 2) occupy many ofthe angles ofjunction .
Genotype:Petalotryp a compressa Ulrich . Devonian. Two spec ies.
DISCOTRYPA U lrich
or with low , broad monticu les ; zooecia thin -walled
, direct ; .apertures
hexagonal or rhomboidal , very regu lar in the ir arrangement
, decreas
ing in size from the centers ofthe monticu les outward ; ne ither meso
pores nor acanthopores present. Genotype:Clustetes elegans
-Ulrich . Ordovician , Devonian. Two
ORB IFORA Eichwald (ORB ITOLITES Eichwald) .
Family BATOSTOMELLIDE Ulrich .
Zoarium usually ramose ; zooeciawith thickwalls in the mature region ,
appearing here tobe fused ; diaphragms in the peripheral region often centrally perforated ; acanthopores and mesopores u sual ly present , the latter small and sometimes moniliform in shape .
B ATOSTOMELLA U lrich (GEINITZELLAWaagen andWentzel) .
Zoarium ramose , branches slender ; zooecia with few diaphragms ;
apertures of zooecia small , c ircu lar or oval ; interspaces rounded or
canalicu late , spinu lose
merous ; mesopores smal l , with subcircu lar openings .
Genotype:B atostomella sp inu losa U lrich . Range , Silurian—Per
mian. Six species .
Zoarium ramose , branches u sually s lender
, sometimes ofconsiderable
size ; zooecia practically without diaphragms ; apertures Oblique , nar rowing above ; interspaces canal icu late ; mesopores few ; acanthopores
comparative ly strong , rarely more than one to each zooec ium
, some
James . Range , Ordov ician—Devonian . Ten described and five new
spec ies .
CALLOTRYFA Hall .
Zoarium ramose ; apertures oval , with equally e levated peristomes
and-with no definite arrangement ; interspaces showing the openings of the numerous mesopores by which the zooec ia are surrounded ; acanthopores present . Genotype:Callopora macropora Hal l . Si lurian
, Devonian. Ten
TREMATELLA Hall .
Zoarium ramose ; more or less conspicuously annu lated ; zooecia obl ique , with a few diaphragms and walls much thickened in the
mature region ; apertures arranged in a somewhat qu incunx order, interspaces ridged
, form ing polygonal areas ; acanthopores sometimes
present . Genotype:Trematopora annu lata Hall . Devonian. Five spec ies .
ERIDOTRYFA U lrich .
Zoarium ramose , branches slender ; zooeciamore or less obl ique , thick
walled , and intersected by diaphragms , which are most numerous and
mom ss w nm am ] DIAGNOSES OF GENERA . 33
-
phragms ; acanthopores small , few
Devonian. Ten described and four new species .
STENOPORA Lonsdale (TUBULICLIDIA Lonsdale , TABULIPORA Young) .
Zoarium ramose , sublobate
, massy , laminar, or paras itic ; surface
smooth or with monticu les ; walls of zooecia thickened periodically in the mature region ; diaphragms sometimes very few , but in most American species abundant in the mature region and perforated cen trally ; mesopores never very numerous , irregu larly distribu ted ; large acanthopores at the junction angles .
Genotype:Stenopora tasmaniensis Lonsdale . M ississippian , Car
boniferous . Seventeen described and three new species .
ANISOTRYPA U lrich .
Zoari um ramose , branches sometimes hollow and lined by an epitheca ;
divis ional line between adjoining zooecia (as seen in sections) sharply defined
, periodical swel ling Ofwalls more or less marked ; diaphragms
centrally perforated , usually numerous ; interspaces generally ridge like ; ne ither acanthopores nor mesopores .
Genotype:Anisotrypa symmetrica Ulrich . M ississ ipp ian. Four
spec i es .
LIOCLEMA U lrich .
, subglobose or incrusting ; surface ire
quently exhibiting distinct monticu les or macu les ; zooecia with sub
circu lar or irregularly petaloid apertures , separated by abundant
angu lar mesopores, which in some species are open at the surface , in
others c losed ; diaphragms few in the zocecia , abundant
, sometimes
crowded in the mesopores ; acanthopores numerou s and strong in the typ ical species , small and inconspicuous in others .
Genotype:Calloporapunctata Hal l . Range , Silurian—M iss issippian.
Twenty - nine described and five new species.
LIOCLEMELLA Foerste .
Zoarium cy lindrical , rare ly branched , pointed at the base (for articu lation2) ; otherwise much as in Lioclema.
Genotype:Callopora o/i ioensis Foerste . Ordov ician , Silurian . Six
described and five new spec ies .
B u ll . 173— 3
34 AMERICAN FOSSIL BRYOZOA (BULL. 173.
THALLOSTIGMA Hall .
Zoarium ramose , frondescent , laminar, or incrusting ; zooecia thin
walled and prismatic in the immature region , with thicker walls and
subcy l indrical when mature ; apertures rounded , peristomes slightly
elevated ; mesopores angu lar, abundant , commonly isolating the zooecia, at intervals gathered into clusters
, which are usually stellate
, closed at
the surface , the closure with numerou s m inu te perforations ; true
acanthopores wanting , but granu les often very abundant on the inter spaces ; diaphragms in both zooec ia and mesopores .
CONSTELLARIA Dana.
Zoarium growing into erect , flattened branches or fronds from a
basal expans ion which is attached to foreign bodies ; surface with depressed stellate macu lae
, the spaces between the rays elevated and
occupied by two or three short rows or clusters of closely approxi
mated apertures ; mesopores aggregated into macu lae , internally with
gradually crowding diaphragms .
Nine described and three new spec ies .
STELLIFORA Hall .
Differs from Constellaria in its incrusting hab it and in hav ing only mesopores in the interspaces between the raised zooec ial clusters .
Genotype and only known species:Stellipora antheloidea Hall . Ordov ician.
NICHOLSONELLA Ulrich .
Zoarium a laminar expans ion , sometimes g iving offflattened inter
twining branches or fronds ; interspaces often granose , interzooec ial spaces wide
, filled with numerous mesopores , which have thicker and
more numerous diaphragms than the zooec ial tubes ; with age the spaces become filled up with a calcareous deposit
, rendering the walls of the
mesopores unrecognizable .
IDIOTRYPA Ulrich .
Zoari um paras itic ; zooecia and mesopores alike crossed by thick dia phragms at short and regu lar intervals
, diaphragms apparently per
forated by numerous m inu te foram ina ; mesopores surround the zooecia, numerous
, irregu lar in Shape
, closed at the surface ; walls with numer
ous m inu te vertical tubu l i or ce lls .
Genotype and only known spec ies:Idiotryp a parasitica Ulrich .
Silurian.
DITTOPORA Dybowski.
Family TREMATOPORIDJE Ulrich .
Zoarium ramose or incrusting ; zooecia irregular in ax ial region , their
prox imal ends with diaphragms and usually constricted where these occur ; wal ls thickened in the mature region ; l ines of contact ofwalls ofadjoining zooecia distinct ; mesopores general ly abundant
, usually
oflarge size , closed at the surface ; acanthopores more or less abundant diaphragms in both zooecia andmesopores .
TREMATOPORA Hal l .
Zoarium ramose ; surface smooth Or with monticu les ; zooecia thin~
walled and with few diaphragms ; a pertures circu lar or oval , with a
more or less wel l -marked peristome ; interspaces sol id ; mesopores
irregu larly angu lar , often Obscure ly monil iform ,
with diaphragms at
‘
. Silurian.
BATOSTOMA U lrich .
Zoarium irregu larly ramose , branches aris ing from a large basal
expans ion ; zooecia with wal ls that are thin in the immature region ,
much thickened and in sections appearing ringl ike (but seldom in con
tact) in mature region ; diaphragms present ; mesopores numerous or
few , irregu lar in size or shape ; acanthopores usually of large s ize and
abundant , sometimes few .
HEMIPHRAGMA U lrich .
Like B atostoma , but diaphragms in mature region of zooecia
incomplete .
STROMATOTRYPA Ulrich .
growing upon fore ign bodies ; zooecia short , with few diaphragms
, the
proximal end scarcely prostrate , oval in cross section ; walls thin , con
taining periodical ly constricted , bead - like tubu l i (modified acantho
pores 2) , one or more to each zooec ium ; apertures oval , separated by
depressed interspaces , the peristomes minu te ly papillose ; mesopores
abundant , beginning on the basal lam ina , decreasing in s ize with age , closely tabulate , the diaphragms fine ly punctured , the ir openings rarely showing
, be ing closed by a common dermal sheet.
Genotype and only desc ribed spec ie s:Stromatotrypa ovata Ulrich .
Ordovician. Three new spec ies.
36 AMERICAN FOSSIL BRYOZOA . [BULL.173.
MONOTRYPA Nicholson (PTYCHONEMA Hal l and Simpson) .
Zoarium massy , hemispherical , subglobose , or discoidal ; zooecia not distingu ishable into mature and immature regions
, comparatively
phragms remote ; ne ither meSOpores nor acanthopores.
Genotype:Oncetetes undulatus Nicholson. Ordovician , Silurian.
Fourteen described and two new species.
DIPLOTRYPA Nicholson (emend . Ulrich) .
Zoarium hemispheric , discoid , globular, or irregularly massy , gen erally free ; zooecia comparatively large , prismatic, with diaphragms ; mesopores few tomany , vary ing in size .
Genotype:Fa/vosites p etropolitan/us Pander. Ordov ician , Silurian.
Four described and two new species.
Family CALLOPORIDE Ulrich.
Zoarium ramose , subfrondescent, or discoidal ; zooecia increas ing in Size very gradually, the ir proximal portion very much like mesopores ;
apertures subcircu lar, the Openings ofa greater or less number of
mesopores interspersed among them , or polygonal , in which case the
mesopores are few or wanting ; no acanthopores.
GALLOFOBA Hal l (emend . Ulrich) .
Zoarium usually ramose , the branches frequently anastomosing and
,
gradually becoming cyl indrical in most cases ; at first with closely set
diaphragms , then diaphragms more distant
, finally in the mature
region diaphragms usuallv c losely set ; apertures closed at times by
perforated , often ornamented covers ; mesopores more or less numer
ous , angu lar
three described and ten new species .
CALLOPORELLA Ulrich .
Zoarium a thin expans ion , free or incrusting ; surface smooth or
undu lated ; zooecia cy lindrical , with thick wal ls and numerous dia
phragms ; apertures circu lar , arranged in regular intersecting series ;
mesopores numerous , angu lar
series ; acanthopores small and few .
Genotype:Calloporella harrisi U lrich Monticulipora (fktcr otrypa) circu laris James . Ordovician. Three spec ies .
Suborder CRYPTOSTOMATAVine. Zooecia short , pyriform to oblong
, quadrate or hexagonal , some
times tubular ; orifice anterior , usually circular ; the upper or front
mom s AND 3m m .) DIAGNOSES OF GENERA . 37
side ofthe zooecium strengthened by a calcareous deposit , sol id or vesicular in nature , which , as it proceeds , leaves an opening above the
orifice , thus producing a shaft or vestibule, which may be crossed by diaphragms or hemisepta.
Family PHYLLOPORINIDE Ulrich .
Zoarium branching ; O
branches free or anastomosing , cellul iferous
on one side only , the other side striated ; zooecia more or less tubu lar, often with diaphragms ; hemisepta wanting.
PHYLLOPORINAUlrich .
Zoarium with branches irregu larly anastomosing , with two to e ight
rows ofapertures on the obverse side , on the reverse longitudinally
striated ; tabu lated interstitial spaces generally present , closed at the
surface ; acanthopores often present. Genotype:Retepora trentonensis Nicholson. Ordovician
, Silurian.
DRYMOTRYPA Ul rich (THAMNOCELLA Simpson) .
Zoarium branching dichotomously at frequent intervals , on reverse longitudinal ly striated ; zomcia in several ranges, ' tubular
, springing
from a thin double plate , beneath which a number ofvesicles (aborted
zooecia2) are present ; vestibu les expanding from the orifices to the angular apertures.
Genotype:Retepora difusa Hal l . Ordovician, Silurian . Four
speci es.
Family FENESTELLIDE King .
Zoarium a reticu lated expansion , cel lul iferous on one side only ,
composed of rigid branches , united by regular nonporiferous bars
(dissepiments) , or branches may be sinuous and anastomose at regular intervals
, or may remain free ; zooecia oblong , quadrate , or hexagonal
in outline , embedded in a calcareous crust which is m inu tely porous ,
especially on the noncelluliferous s ide ; orifice anterior , semielliptical
,
times by a centrally perforated closure ; a superior hemiseptum gen
erally present, an inferior one less frequently .
FENESTELLA Lonsdale (ACTINOSTOMA Young and Young , FLABELLI
PORINA Simpson) .
Zoarium flabellate or funnel shaped , cellu liferous on the inner side ;
branches generally straight , sometimes flexuous
, connected at regular
intervals by dissepiments ; apertures in two rows , separated by a
plain or tuberculated median keel .
38 AMERICAN FOSSIL BRYOZOA . (BULL.173.
Genotype:Gorgonia antigua (Goldfuss 2) Lonsdale . Accepted geno type:F enestella plebeia McCoy . Range , Ordov ic ian—Carboniferous. One hundred and e leven described and a considerable number of new
spec ies .
SEMICOSCINIUM Prout (CRYPTOPORANicholson , CARINOFORANicholson, CYCLOFORINA Simpson) .
Zoarium funne l shaped , cellul iferous on the ou ter side ; dissepiments
wide , very short
poriferou s face , where the fenestrules are subrhomboidal or rounded ;
apertures in two rows , median keel very high and expanded at the
summi t . Genotype:Semicoscinium rhomboideum Prout. Silurian
, Devonian.
Zoarium as in Semicoscinium, except that the reverse ofthe zoarium
and the expanded summits ofthe carinae bear large scattered pores or pits .
Genotype:Fenestrapora biperforata Hall . Devonian. Three spec ies .
ISOTRYPA Hal l (TECTULIPORELLA Simpson) .
Zoarium funnel - shaped , branches connected by dissepiments ; aper
,
expanded at the summit ; summits connected by round or oval lateral bars
, usually si tuated above the dissep iments ; on the reverse face a
more or less conspicuous pore occurs on or near each dissepiment. The superstructure gives the obverse much the appearance of the
reverse ofthe zoarium .
spec ies .
, typically
reduced to a m inimum , nonporiferou s dissepiments ; apertures in two
rows ; branches and dissepiments carinated , the carinae coalesc ing ;
summits of carinae much expanded , angu lar
, and slightly carinated
,
their width u suallv equaling that of the branches and dissepiments below and hence cau sing difli culty in distingu ishing the obverse and
reverse s ides .
spec ies .
UNITRYPA '
Hall .
Zoarium funne l - shaped ; branches connected by dissep iments ; aper tures in two rows
, separated by a carina ; carinae prominent , thickened
THAMNISCUS King.
Zoarium as in Polypora, but branches bifurcate more frequently and
are rare ly or not at all connected by dissepiments .
Genotype:Oeratop /zytes dubius Schlothe im . Range , Silurian—Car
boniferous . T hirteen spec ies.
PHYLLOPORA King.
Zoarium funnel - shaped , ce llu l iferous on the ou ter face ; fenestrules
oval , branches anastomosing or connected by broad celluliferous dis
sepiments ; zooecia in two ranges normal ly ; without median kee l . Genotype:Gorgonia ehrenbergi Geinitz. Devonian. One species .
RETEFORIDRA ( z RETEFORELLA Simpson)1 (ANASTOMOPORA Simpson) . Zoarium a flabellate or undu lating expansion with thickened mar
gins ; branches sinuous or zigzag , anastomosing at short and regular
intervals so as to produce a regu lar series ofoval fenestrules ; aper tures in three to seven rows ; branches withou t a median carina.
Genotype:Retepora undulata Simpson z Fenestella p erundata Hall . Devonian. Three species .
RETEFORINA D’Orbigny .
Zoarium as in Reteporidra, but the zooecia are in two ranges , with the apertures separated or not by a more or less well -marked median carina.
Genotype:Retepora prisca Goldfuss . Devonian , M ississippian.
Eight species .
sizes , the smaller or secondary branches proceeding laterally from the
larger or primary ones, ei ther from one or both sides ; as the frond expands
, other large branches proceed from the primary ones
, this
process continu ing during the growth of the frond ; apertures in two
,
, PINNAPORINA
Simpson) .
Zoarium l ike that ofPtiloporella in mode ofgrowth , but branches have three or more rows ofapertures and nomedian Carina.
Genotype:Fenestella (Ptiloporina) conica Hall . Devonian. Four
species .
l Reteporidra is proposed forReteporella , preoccupied by B usk , Challenger Report, X , 1884, p. 126.
wom e n » B i ssma l DIAGNOSES OF GENERA . 41
Family ACANTHOCLADIIDZE Zittel .
Zoarium a pinnate or fenestrate expansion , celluliferous on one face
only , consisting of strong central stems which give Off numerous
smaller, lateral branches from their margins ; the lateral branches are free or unite with those ofthe next stem ; nonporiferous dissepiments rarely present ; zooecial characters mostly as in the Fenestellidae.
PINNATOPORA V ine (GLAUCONOME ofauthors) .
Zoarium a smal l de licate stipe , with short, free lateral branches given off frequently and at regular intervals ; apertures in two rows
, sepa
rated by a moderate median kee l. Genotype:Glauconome elegans Young and Young . Range
, Devon
ACANTHOCLADIA K ing.
Zoarium as in Pinnatopora , but larger and stronger and with three or more rows ofapertures between which the surface is e levated into smal l longitudinal ridges or series oftubercu les .
Genotype:Oeratop liytes anceps Schlothe im . Carboniferous . One
species .
Zoarium a fenestrate , flabellate or leaf - like expansion ; primary
branches numerous , increasing by b ifurcation or interpolation ; the lateral branches unite with those from the adjacent primary branches ; apertures in two rows on primary and lateral branches ; reverse usually with fine striae and scattered dimorph ic pores.
Genotype:Sep topora cestriensis Prout . M ississippian , Carbonif
erous . Eleven species.
SYNOCLADIA King.
Zoarium as in Septopora, but branches stronger and with three or more rows of apertures , usual ly between e levated ridges .
Genotype:Retepora virgu lacea Phillips . No American species known.
PTILOFORA McCoy (DENDRICOPORA De Koninck) Zoarium pinnate
, the stipe much stronger than the Obl ique lateral
branches , which are occasionally and irregularly united by dissepi
ments ; apertures in two rows .
Genotype:P tilopora p luma McCoy . Devonian , M ississippian.
Eight species .
ICHTHYORACHIS McCoy .
Zoarium as in Ptilopora, but the stipe bears five or more rows of apertures and the branches usually three .
Genotype:Ichthyorachis newenhami McCoy . Silurian. One
species.
DIPLOPORARIA ( z DIFLOFORA Young and Young) . 1
Zoarium as in Pinnatopora, but has no lateral branchlets .
Genotype:Dip lopora marginalis Young and Young . M ississip p ian
, Carboniferous . Two species .
RAMIPORA Tou la.
Family - SPHRAGIOPORIDJE Ulrich .
, circu lar
, subhemispheric patches
on foreign bodies ; zooecia ofthe same type as in Feneste lla ; apertures c ircu lar, with a sl ight peristome
, arranged in one or two rows on the
summits of slightly elevated , radially arranged
, broad ridges ; spaces
Genotype and only known species:Sphragiopora parasitica Ulrich .
M ississippian.
Family ARTHROSTYLIDZEUlrich .
,
united into small p innate or bushy colonies , or ofcontinuous
, dichoto
mously divided branches ; zooec ia subtubular , more or less obl ique ,
radially arranged abou t a central axis , and opening on all s ides of
the segments ; or one s ide may be noncelluliferous and longitudinal ly striated .
ARTHROSTYLUS U lrich (Arthronema Ulrich) .
Zoarium bushy , dichotomously branching , the whole consisting of numerous exceedingly slender, equal , subquadrate segments
, united
by term inal articu lation ; one face longitudinally striated , on each of
the other , commonly three , faces a linear series ofapertu res between
longitudinal ridges .
HELOPORA Hall .
Like Arthrostylus , but the segments are general ly larger and hav i zooecial apertures on all sides .
Genotype:Heloporafragilis Hall. Ordovician, Silurian. Twelvl
Species .
ARTHROCLEMA Bil lings .
Zoarium ofsegments ce llu liferous on all sides , articu lated terminall '
and laterally in a pinnate manner ; apertures oval , in series betwee
longitudinal ridges .
Genotype:Arthroclema p u lc/i ellum B illings . Ordov ician. Si Species .
lDiploporaria proposed for DiplOpora , preoccupied by Schafhautl.
mcm s w nm ssw a l DIAGNOSES OF GENERA . 43
SCEPTROPORA Ulrich .
Zoarium of segments which become much expanded in their upper portion and at the top have a socket for the articu lation ofthe next segment ; lower portion striated , withou t apertures ; upper part w ith apertures all around ; apertures subovate ,
in l inear series between lon
gitudinal ridges .
species .
Zoarium very slender, ramose , continuous above the pointed basal extremity ; zooecia subtubular, arranged radially around one or two
minute axial tubes ; apertures oval or subcircular ; with peristome ,
generally in linear series between longitudinal ridges .
Genotype:Nematopora ovalis Ulrich . Range , Ordovic ian—Devo~
nian. Fifteen species .
Family RHABDOMESONTIDZE Vine.
Zoarium ramose or simple , not articulated , sometimes with an axial tube
, but generally solid
, in which case the ax ial region is occup ied by
thin -walled primitive tubes , with or withou t diaphragms ; hem isepta
usually present , but never conspicuous ; apertures circu lar or oval ,
usually in linear series between longitudinal elevated ridges , or in diag onally intersecting series ; vestibu le a rhombic or hexagonal s loping area ; meSOpores general ly absent.
RHOMB OPORA Meek .
region ; aper tures in longitudinal or diagonally intersecting series ; acanthopores present , sometimes oftwo kinds
, large and small .
Carboniferous . . Twenty - nine described and several undescribed species.
RHABDOMESON Young and Young .
Zoarium with a slender axial tube , to which the proximal ends of
the zooecia are attached ; otherwise like Rhombopora .
Genotype:M illepora gracilis Phillips ; from the Carboniferous of England and Scotland . No American species have yet been made known.
C( ELOCONUS Ulrich .
Zoarium simple , hollow
ate '
d , striated base ; zooecia short , with well developed hemisepta , aper
tures in diagonal ly intersecting series .
Genotype:Uazloconus rhombic us Ulrich . M ississippian . Two
species.
BACTROFORA Hall .
otherwise as in Rhombopora.
pian. Three species .
ORTHOPORA Hal l .
Zoarium ramose , sol id ; apertures in parallel longitudinal rows, with
ridges between ; acanthopores present . Genotype:Trematopora regu lar
-is Hall . Silurian, Devonian.
Twenty - six spec ies .
Zoarium slender , ramose ; zooecia tubu lar, arising from a filiform
axis in the center of the branch ; apertures oval , in diagonally inter secting series, or linear series separated by ridges ; vestibules polygonal , broadly slop ing ; acanthopores between the apertures .
Genotype:Trematopora alternata Hall . Devonian , M iss issippian.
Six spec ies .
Zoarium slender , ramose ; zooec ia long , tubular, diverging obl iquely
from a central filiform ax is , near the surface bending abruptly ; inter
spaces solid ; apertures oval , in linear series , separated by ridges , with
very thin, slightly elevated peristomes ; on the surface at intervals there are monticu les destitu te of cel l apertures
, which extend around
Genotype:Nanatazcisfibrosu s Hall . Devonian. Two species .
TROPIDOPORA Hall .
Zoarium slender , ramose ; apertures in i rregular longitudinal series ,
separated by sinuous ridges , with very thin sl ightly elevated peristomes .
Genotype and only known species:Trop idopora na/ na Hall . Devonian .
STREB LOTRYPA Ulrich .
Zoarium ramose , slender
, solid ; zooecia long , tubular, diverging
from the center ; inferior hemiseptum best deve loped , situated rather far down ; apertures regularly e ll iptical
, with peristome
, usually
arranged in longitudinal series ; be low the apertures there are from one to twelve or more small pits
, arranged
, Carboniferous.
HYPHASMOPORA Etheridge , J un.
From the Carboniferous ofScotland .
, which are undu lated
, or subtubular ;
apertures large , with thin interspaces in several rows , arranged in
acu te ly diagonally intersecting series .
Genotype:Chainodictyon laceum Foerste . Carboniferous . Two
spec ies.
Zoarium bifol iate , composed oftwo layers ofzooec ia, grown together
back to back , usually jointed , at least at the base , and forming leaf - like
expans ions or compressed branching or inoscu lating stems ; mesotheca
withou t median tubu l i ; zooecia usually have hemisepta and semiellip tical orifices ; apertures usually ovate , surrounded e ither by a slop ing area or a ringlike peristome ; vestibu les separated by thick walls .
PTILODICTYA Lonsdale (HETERODICTYA Nicholson) .
Zoarium a simple , unbranched
, lanceolate or falciform frond
, narrow
or wide , which articu lates with a smal l basal expansion ; in the young
condition the zoarium consists of longitudinal ly arranged , narrow
oblong -
quadrate zooecia, new zooecia of different width and arrange ment be ing added subsequently on each side ; walls ofvestibu les thick solid
, and with a double row ofminu te dots .
Genotype:F lustra la/nceolata Lonsdale . Ordov ic ian , Silurian . Six
teen spec ies.
ESCHAROFORA Hall (NICHOLSONIAWaagen andWentzel) .
Like Ptilodictya, but distingu ished chiefly by the arrangement of the apertures
, which are in decussating series
, and by the slop ing
hexagonal area which surrounds the apertures .
Genotype:Escharop ’
ora rectaHall . Ordovician. Fourteen described and e leven new species .
CLATHROFORA Hall .
Zoarium composed ofanastomosing branches , forming a regu lar net work with round or oval fenestrules
, with a pointed
species.
PHzENOFORA Hall .
Like Ptilodictya, except that there are two mesopores in each inter space between the ends ofthe apertures .
Genotype:Phcenopora emp lamata Hall . Ordovic ian , Silurian Fourteen species .
ARTHROPORA Ulrich .
Zoarium bushy , composed Ofnumerous articu lating equal segments , pread in a p lane ; apertures e l liptical
, surrounded by a del icate peri
stome ; interspaces with one or more thread - l ike ridges variously dis posed
, and with a row ofminute papillae.
Genotype:Stictopora (Pti lodictya) snaferi Meek . Ordovic ian.
Five described and four new species.
GRAFTODICTYA Ulrich .
Zoarium a narrow bifurcating frond with a pointed base articulating with a smal l basal expans ion ; apertures subcircu lar, surrounded by a
peristome subpolygonal in ou tline ; interspaces depressed , usually with one or two fine tortuous elevated lines .
Genotype and only known species:P tilodictya elegans U lrich .
Ordov ician.
Zoarium a simple or branching frond , from an obtusely pomted
articulating base ; apertures oval , in decussating series
, inc losed ill
Genotype:Trematopora clav ij '
OPORELLIDE .
This fam ily differs from the Ptilodictyonidae mainly in that the zoarium is not articu lated , but grows upward from
, and is continuous
STICTOFORELLA Ulrich .
Zoarium branching , cribrose , or leaf - like ; zooecia with the primitive portion tubular
, usually long , general ly withou t hemisepta, the inferior
one only occasionally present ; orifices at the bottom Ofa wide , sloping
vestibu le ; thick -walled , untabu lated mesopores occur between the
apertures and line the margins ofthe zoarium .
Genotype:StictOporella in terstincta Ulrict tilodictya flezcuosa James . Ordovician . Nine described and four new species .
PTILOTRYFA Ulr ich .
Zoarium ramose , with compressed or frondescent branches ; surfac ¢ with irregular longitudinal ly channe led areas appearing like maculae
by numerous , irregular
, th ick -walled
, tabulated mesopores , which are
also clustered at intervals intomacu lae ; orifices c ircu lar , at the bottom
ofthe sloping vestibu le .
M iss issippian .
Family RHINIDICTYONIDJE Ulrich .
Zoarium b ifoliate , continuous or jointed , consisting of compressed branches or leaf - l ike expansions ; occasionally trifoliate ; zooecia sub
quadrate , arranged longi tudinally , inferior hemiseptum wanting ; ori fices and apertures el liptical or subcircu lar, sometimes a l ittle truncated posteriorly ; median tubu l i between the median laminae and between the longitudinal rows of zooec ia ; mesopores wanting , but vesicular tissue often deve loped .
RHINIDICTYA Ulrich .
, compressed
, attached to fore ign
bodies by a continuous expanded base ; apertures in longitudinal series betweensl ightly e levated or flexuou s ridges
, carry ing a crowded row
of small blunt spines ; space immediately surrounding the apertures sloping up to the summits ofthe ridges .
Genotype:B itinidictya nicholsoni Ulrich . Ordovi cian. Nineteen speci es .
EURYDICTYA U lrich .
Zoarium a broad , simple or irregularly divided , b ifoliate expansion ;
surface with more or less consp icuous , smal l , solid maculae or monti
cu les ; structure '
ei es .
, with parallel marg ins ,
, nonporiferous margins ;
surface with smal l macu lae , surrounded by apertures s lightly larger
than the average ; sometimes the marginal rows ofapertures are also slightly larger than the average ; zooecia with thin walls , e lliptical or subquadrate in shape
, separated from adjoining zooec ia by small
vesicles ; vestibules direct , walls thickened and appearing ringl ike in sections ; spaces between vestibu les traversed by one or more series of m inu te tubul i ; one or more diaphragms developed ; apertures com
monly e lliptical ; interspaces usual ly forming a peristome about the apertures.
Genotype:Pacfipdictya robusta U lrich . Ordovician , Silurian.
Twenty -five described and several new spec ies.
cxm s w n B i ssm a l DIAGNOSES OF GENERA . 49
PHYLLODICTYA U lrich .
Zoarium simple or irregu larly branched , growing from an expanded basal attachment ; zooecia long , tubu lar, w ith diaphragms but no hem i septa, bending very gradually ou tward from the central axis
, thus
causing the apertures to be more or less strongly oblique , with the posterior edge liplike ; interspaces wide , subsolid , traversed vertically by one or two rows ofminute tubu li
, which appear as papillae at the
surface .
Ci es .
EUSFILOPORA Ulrich .
Zoarium consisting ofsmal l , irregu larly divided branches , with ser
rated or wavy edges ; apertures in four or more linear series on the
middle of the branch , between slightly e levated longitudinal ridges
bearing numerous smal l nodes ; alternate ly on the two sides are short rows directed oblique ly upward ; between the ends ofthe zooecia shal low
, lenticular vesicles are found ; interspaces traversed vertical ly by
numerous m inute tubuli . Genotype:Eusp ilopora serrata Ulrich . Devonian. Four spec ies .
DICRANOPORA Ulrich .
Zoarium jointed ; segments l igulate , rare ly S imple , usual ly bifurcat
ing at the upper end; each extrem ity somewhat thickened ; minu te structure ofzooec ia and arrangement ofapertures as in Rhinidictya.
Genotype:Ptilodictya in ternodia M iller and Dyer. Ordov ician Silurian. Five species .
GONIOTRYFA Ulrich .
Zoarium with a prominent median ridge upon both sides of the
double - leaved segments ; otherwise l ike Dicranopora.
Genotype and only known Species:Goniotrypa bilateralis Ulrich .
Ordov ician TRIGONODICTYA Ulrich .
Aoarium oftriangular branches , constructed upon the plan ofPris
mopora , but with zooecia and all m inu te details of structure as in
Pachydictya.
Two described and two new spec ies .
Family CYSTODICTYONIDE Ulrich.
Zoarium consisting oftwo or. three layers of cells grown together back to back
, form ing branching
50 AMERICAN FOSSIL BRYOZOA . [m a 173.
expansions or triangu lar branches ; zooecia semicordate or Obovate acuminate in outline
, arranged longitudinally ; orifices subc ircu lar
,
vestibu le e longated ; apertures with peristome and more or less well deve loped lunarium ; interzooecial spaces occupied by ves icu lar tissue often filled with a calcareous deposit near the surface .
CYSTODICTYA Ulrich (ARCANOPORAV ine , STICTOCELLA Simpson) .
Zoarium ramose , branches sharply ell iptical in cross section , with
subparallel , nonporiferous margins ; apertures subel liptical , in linear
eries between longitudinal ridges , which may not always be present, lunarium on the side ofthe aperture neares t the margin ofthe branch ; interspaces finely striated
, granu lose or smooth ; pits and cel ls Show
only in a worn condition.
Genotype:Uystodictya ocellata U lrich . Range , Devonian—Carbon
iferou s . Thirty - five species .
DICHOTRYPA Ulrich .
lee ; otherwise as in Cystodictya.
Genotype:Dichotrypa foliata Ulrich . Devonian , M ississippian.
Seven species .
Zoarium offlattened branches , cellu l iferous on both s ides
, which
inoscu late at short intervals till there is produced a broad frond , per
forated at rythmical intervals by circular or e ll iptical fenestrules ; in other respects like Cystodictya.
Genotype:Coscinium cyclop s Keyserl ing . Range , Devonian—Car
boniferous . Five spec ies .
TrENIOPORA Nicholson (PTEROFORA Hal l , STICTOFORIDRA Simpson) .
Zoarium with a strongly e levated longitudinal central ridge on each face
, SO that a cross section of the branches is somewhat rhomboidal ;
otherwise like Cystodictya.
THAMNOTRYPA Hall (Thamnopora Hall) .
Zoarium consisting ofa very narrow stipe , from which proceed rectangularly lat
eral branches ; ce l lu l i ferous on each face ; cel l apertures oval ; usual ly disposed in two paral le l longitudinal rows
, separated by a prom inent ridge . Sometimes three
rows occur and occasionally four rows for a short distance on th e stipe . On th e lat
eral branches there are never more than two rows .
l
Genotype and only known species:Tliamnopora divaricata Hall. Devonian.
1 Simpson, Fourteenth Ann .Rep. State Geolog ist New York for th e year 1894, p. 546.
S camAND BASSLERJ DIAGNOSES OF GENERA.
SEM IOFORA Hall .
, proceeding from a Spread
ing base ; branches narrow , with paral lel margins and a narrow non
ce llul iferous marginal space ; interzooec ial spaces occupied by vesicu lar tissue ; apertures oval or subcircular
, regu larly disposed in parallel
longitudinal rows ; apertures largest i ll marginal rows ; be tween the
apertures in a longitudinal direction are the openings of two small mesopores side by side .
Genotype and only known species:Semiopora bistigmata Hall . Devonian.
PTILOCELLA Simpson.
, striated base ; apertures c ircu lar,
arranged in paralle l , longitudinal rows, separated by ridges ; marg ins of frond striated , non- celluliferous .
Genotype andonly known spec ies:P tilodictyaparallela Hall. Devo nian
ACROGENIA Hall .
proceed from the truncated termination ofthe proceeding one ; segments obconical and striated at the base , gradual ly becom ing flattened and
showing apertures ; apertures largest in themarginal rows , with prom inent lunarium
, in linear series separated by ridges .
Genotype and only known species:Acrogenia prolif '
eraHall . Devo nian.
, b ifurcatingor trifurcating branches ,
sometimes anastomosing and forming clumps ; branches with the sides subequal , usual ly a little concave
, edges sharp
, sometimes serrated or
wavy ; zooecia arise from mesothecae which radiate from the center to the margins ; apertures vary ing in arrangement
, sometimes on the
summits ofsmal l papi llae ; structure otherwise as given for the family Genotype:Prismopora triqu etra Hall . Range
, Devonian-Carbon
SCALARIFORA Hall .
Zoarium with the faces Ofthe triangular branches crossed by salient transverse ridges ; otherwise like Prismopora.
Genotype:Scalaripora scalariforvnis Hall . Devonian. Five spec ies.
GLYFTOFORA U lrich .
Zoarium a thin expansion , traversed on both surfaces by salient
ridges or crests , uniting so as to form larger or smaller cup
- shaped
52 AMERICAN FOSSIL BRYOZOA . (BULL . 173.
cavities ; or a uni laminate base on which the ridges are greatly deve l oped and form large leaves ; these ridges or leaves are composed of
two layers ofzooecia growing in opposite directions from amesotheca ;
in the angles ofeach cup is a depressed noncelluliferou s furrow which with sim i lar furrows in neighboring cups produces a th in junction between the leaves ; surface ofthe ridges and of the cups with elon gated solid macu lae or“dimples ;” structure otherwise as given for the fam ily .
Genotype:Coscinium p lamosum Prout . M ississippian. Eight spe cies .
PHRACTOPORA Hall .
Like Glyptopora except that the apertures are re latively more
rounded and larger , and the junction angles are cellu liferous and thicker
than any other part ofthe leaves .
Genotype:Phractopora cristata Hall . Devonian , M ississippian.
Four species .
CERAMELLA Hall .
Zoarium consisting of thin , fol iaceous expansions, arising from a spreading bas e ;
ce llul iferous on each face ; cel ls tubu lar, oblique ; ce l l apertures oval or circu lar, dis posed . in qu incunx order ; surface marked by steri le macu lae , which are usual ly depressed be low the general surface ofth e branch .
1
vonian.
, arranged
,
thick , and nonporiferou s in the basal portion ; apertures on both faces
of the leaves or rays , subcircular ; interspaces solid at the surface occupied by vesicu lar tissue internally .
Genotype:Evactinopora radiataMeek andWorthen . M ississippian.
Four species .
Family ACTINOTRYPIDJE Ulrich
ACTINOTRYPA Ulrich .
Zoarium a thin bifol iate expansion ; apertures show the proj ecting ends of from e ight to ten vertical septa- l ike ridges that extend down along the sides of the vestibule nearly or qu ite to the orifice .
Genotype and only known species:Fistu liporap ecu liaris Rominger.
M ississipp ian.
I Simpson , Fourteenth Ann . Rep. State Geologist New York for th e year 1894, p. 527,
NICKLES AND BASSLERJ DIAGNOSES OF GENERA. 53
Family CYCLOPORIDE .
CYCLOPORA Prout.
, hemisepta
,
which usually have a central perforation and are Open at the surface ; apertures subcircu lar
, with a smooth or granu lose peristome ; acan
thopores sometimes present . Genotype:Cycloporafungia Prout . M ississippian. Two spec ies.
CYCLOFORELLA U lrich .
Zoarium a thin discoidal expansion ; zooecia subtubular ; vestibu l es with a succession of superior hemisepta ; irregular mesopores abun
dant ; numerous acanthopores of large size .
Genotype:Cycloporella sp inifera Ulrich . M ississipp ian. Two
species .
wrinkled epitheca ; zooecia subtubular, th in - walled ; apertures broad elliptical
, surrounded by a narrow sloping area
, hexagonal in ou tl ine ;
when perfect the apertures have a depressed calcareous plate that closes a little less than two- thirds ofthe opening
, the orifice left being
, and Situated at the
anterior Side ; with age the vestibu les become elongated and are inter sected by incomplete diaphragms .
Genotype and only known species:Cyclopora discoidea Prout. M is sissippian.
WORTHENOPORA Ulrich .
Zoarium b ifoliate , branch ing or palmate ; zooecia very regu larly
arranged , e longate rhomboidal ; apertures semielliptical , the truncated
posterior margin somewhat raised ; on the surface the line ofj unction between ad joining zooec ia is marked by an e levated ridge ; the e longate triangular space be low the apertures perfectly plain .
Genotype:Wort/tenopora sp inosaUlrich . M issi ssipp ian. Twospecies .
Fami ly RHINOPORIDE Ulrich .
Zoarium variable in form ; zooec ia prone along the basal membrane
simple , Oblong
, or rhomboidal ; vestibu les direct, hemisepta wanting
or almost so; front of zooecia be low vestibu le commonly strengthened with solid or vesicu lar tissue .
54 AMERICAN FOSSIL BRYOZOA. [3 9mm
RHINOFORA Hall .
,
and traversed by slender, rounding, bifurcating ridges , which appear
as shal low grooves when the surface is worn ; apertures nearly c ircu lar, occupy ing the summ its ofpromi