9
xxv pomona and its extreme form catilla; both upper and under surfaces being shown. The specimens are all females; a gradation also exists in the males, though in this sex there is far less difference between the forms a t the crocak and posnona ends of the series. Papers. The following papers were read :- 1. " On Fluorescence in Lepidopterous Pigments," by Dr. 2. " On the Species of the Genus Cos?riophila," by Mr. 3. " On thq Dragonflies of Palestine," by Mr. K. J. MORTON. 4. " On the Metamorphosis of Deuterophlebia sp. (Diptera, E. A. COCKAYNE. W. H. TAMS. Deuterophlebidae, Edw.)," by Miss PULIKOVSKI. Wednesday, April 2nd, 1924. Mr. E. E. GREEN, President, in thc Chair. Obituary. The PRESIDENT announced the death of Dr. L. P~IRINGUEY, Director of the South African Museum, Cape Town, and : t Fellow of the Society. Election, of Fellows. The following were elected Fellows of the Society:- Mr. E. T. ELLIS, The Firs, Bridge Street, Wye, Kent; Mr. F. D. GOLDING, Moor Plantation, Ibadan, Nigeria ; Mr. W. E. JONES, M'fongosi, Zululand. Exhibits. A NEW RACE OF AMAURIS LOBENGULA E.M.Sh., FROM S.E. OF LAKE RUDOLPH, FLYING WITH A CORRESPONDING 9 F. OF PAPILIO DARDANUS BRoU".-prof. POULTON communicated the following account of these very interesting new forms, received in a letter from Dr. V. G. L. van Someren. '' Nairobi, September 12, 1923. " Now for a bit of news which has pleased me greatly. 1 can find no record of it in the little literature at my dispos:ai :

Wednesday, April 2nd, 1924

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xxv

pomona and its extreme form catilla; both upper and under surfaces being shown. The specimens are all females; a gradation also exists in the males, though in this sex there is far less difference between the forms a t the crocak and posnona ends of the series.

Papers.

The following papers were read :- 1. " On Fluorescence in Lepidopterous Pigments," by Dr.

2. " On the Species of the Genus Cos?riophila," by Mr.

3. " On thq Dragonflies of Palestine," by Mr. K. J. MORTON. 4. " On the Metamorphosis of Deuterophlebia sp. (Diptera,

E. A. COCKAYNE.

W. H. TAMS.

Deuterophlebidae, Edw.)," by Miss PULIKOVSKI.

Wednesday, April 2nd, 1924.

Mr. E. E. GREEN, President, in thc Chair.

Obituary. The PRESIDENT announced the death of Dr. L. P~IRINGUEY,

Director of the South African Museum, Cape Town, and :t

Fellow of the Society.

Election, of Fellows. The following were elected Fellows of the Society:-

Mr. E. T. ELLIS, The Firs, Bridge Street, Wye, Kent; Mr. F. D. GOLDING, Moor Plantation, Ibadan, Nigeria ; Mr. W. E. JONES, M'fongosi, Zululand.

Exhibits. A NEW RACE OF AMAURIS LOBENGULA E.M.Sh., FROM S.E.

OF LAKE RUDOLPH, FLYING WITH A CORRESPONDING 9 F. OF

PAPILIO DARDANUS BRoU".-prof. POULTON communicated the following account of these very interesting new forms, received in a letter from Dr. V. G. L. van Someren.

'' Nairobi, September 12, 1923. " Now for a bit of news which has pleased me greatly. 1

can find no record of it in the little literature a t my dispos:ai :

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xxvi

it is this. One of my collectors has just returned from Marsabit and Karoli, S.E. of Lake Rudolph. In his butterfly collection are several 9 P. dardanus, not the Abyssinian forms but females which mimic the two dominant Amawris of the dis- trict-A. niavius dominicanus Trim., and a species with markings coloured like those of the Abyssinian A. steckeri Kheil. Out of 18 99, twelve arc of the cenea form, but with every spot oclwe as in the last-mentioned Amauris, of which there are eight specimens. In the series this is most striking- this form of 9 dardanus does not occur in the series I have from Kenya or Uganda. The specimens are as large as P. dardanus from Uganda. The dd are large and nearer to yolytrophus Jord., than to tibullus Kirb.”

An example of the new race of Amauris, a form of lobenguh E.M.Sh. and of its mimic, kindly sent by Dr. van Someren, were exhibited to the meeting, together with a specimen of A . steckeri from Abyssinia, showing similarity in the colour of the markings and suggesting the probability that the two Danaines overlapped and were mimetically associated t o the north of the area where the collection was made. The fact that the male P. dardanus was not heavily marked like the East Coast tibullus also suggested transition towards the lightly inarlied Abyssinian alztinorii, and interbreeding between the two races further to the north. On the other hand, the black-and-white Amauris, being of the race dominicanus, was the regular East Coast race and differed from the Abyssinian form of niavius L. in which the white patch of the hind-wing is smaller like that of ninvius riiavius L. from the Victoria Nyanza to the West Coast.

Amawis lobengula septentrionis s.-sp.n.-Differs from the Southern races lobenyula lobengula E.M.Sh. (whytei Butl.), crawsliayi Butl., and katawgae Neave, in the dark ochreous tint of all the markings. The subapical series of spots in the fore-wing of the type forms a nearly continuous bar with the submarginal spot, instead of being separated from it‘by a wide interval ; the difference is due to the size and shape of the spots and not to any additional element. A good series of septentrionis is required in order to decide how far this slight

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difference in pattern is characteristic. Dr. van Someren's statement (p. xxvi) proves that 'there is no doubt about the constancy of the important colour difference.

T y p e : 8, from Marsabit, S.E. of Lake Rudolph: July 1923. In Hope Dept., Oxford University Museum. One of eight examples received from Marsabit by Dr. van Someren.

The name is intcnded to direct attention to the gap between the area occupird by this race and those from further south, represented in the British Museum and the Hope Department by examples from Rhodesia, Katanga, Nyasaland and Southern Tanganyilm Territory ; in the Tring Museum irom Nyasa- land to Ruwenzori. It is probable that the gap will be diminished by future discoveries, but that it will always remain great.

It is to be noted that Dr. van Someren niakes no mention of Ainawris albimnczilntn Butl., arid it may be safely concluded that it was absent from the Marsnbit collection. Albimaculata is also absent from tlic Abyssinian and Somali series of Amaicris in t h e Triiig Museum, kindly examined by Dr. Karl Jordan. It would be of interest to determine the precise northern limit of the range of a species which accompanies A. echeria southward into Natal and probably to its southernmost locality in Cape Colony.

Papilio dardanus Brown, n. Q f. cenea ochracea.-Differs from cenea in the drep ochreous colour of all the markings, harmonising with but somewhat paler than those of its model A. lobenguln septentiionis.

T y p e : 9, from Marsabit, S.E. of Lake Rudolph: July 1923. In Hope Dept., Oxford University Museum. One of twelve examples received from Marsabit by Dr. van Someren.

This form is a vcry interesting addition to the cenea female forms of dardunvs. It is probable that the same form or one very closc to it exists as a mimic of Amazrris ellioti Butl., as suggestcd by Dr. G . D. H. Carpenter in the following pas- sage :-" On a rrturn journey from Kigezi to Kabale I saw on the 25th Feb. a 3 P . dctrdanus in the valley where the Amnzwis [ A . ellioti], new to me, with butter-yellow spots, anil large yellow area a t base of h.-w. ~ I ~ O I V , is so common. How

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nice if the local 0 cenea copied this-for echeria is not nearly so common, though it occdrs with the other.” (€’roc. Ent. SOC., 1916, pp. cxxi, cxxii.)

Probably the most interesting and convincing detail in the mimicry of the female forms of dardanus is the local change of tint in harmony with change in the Danainc models. The new example now brought before us by Dr. van Soineren is a striking addition to others already known, but not I think hitherto recorded. Thus specimens kindly presented to the Hope Dept. by Canon St. Aubyn Rogers sliow that on Dabida Mountain, near Taveta, Kenya Colony, the markings of Amauris echeria and still more markedly A . albimamlata are remarkably pale, in fact nearly white, and that this tint is mimicked not only by the cenea female of dardanus, but by the female P. echerioides Trim., and by local forms of Acraea johnstoni Godm. and A . esebria Hew. On the other hand, the hind-wing patch of Hypolinznas (Euralia) inimu Trim., probably because it belongs to a group with more wandering habits strongly exemplified by H . misippus L. and H . bolina L., is of the deeper tint characteristic of its models over by far the largest part of their range, and occurring in localities near to Dabida, e . 9. on Kilimanjaro, where Canon Rogers captured A . echeria and albillzacztlata with the similarly-tinted cenea female, between January 5 and 16, 1906.* A series collected in 1907 and 1908 by Mr. C. P. M. Swynnerton a t Chirinda, S.E. Rhodesia, showed the same yellowish markings on A . albimaczclata and lobengzlla lobengula which here replaces the closely allied echeria. The tint was followed by the Chirinda cenea females and the females of P . echerioides. Similar markings are gcneral in the two Natal species of Anaauris and their mimics, of which examples, captured at Malvern, near Durban, on March 25, 1897, by Dr. G . A. Ii. Marshall, P.R.S., are recorded in Trans. Ent. SOC., 1902, p. 485. A . albimuculata, quoted as a var. of echeria, was the model taken on this occasion.

Finally, with much surprise and interest; I received from

* These specimens were exhibited to the meeting together with the Dabida series taken by Canon Rogers between March and September, 1916, and the types of Dr. van Someren’s new races from Marsabit.

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Dr. G. D. H. Carpenter several pale-marked members of this association taken together a t Isipingo on the Natal coast 10 miles S. of Durban. They included examples of Aniawis echeria, the ceiaea female of dardanus, Psezcdacraea lucrefia tarqzcinia Trim., and Acraea esebria, all captured May 9-23, 1918, except the esebria (April 2). It will be of much interest to determine the limits of this pale-marked association and to ascertain how far Hypolimnas mima keeps true to it.

These isolated associations, each in a limited area, closely surrounded by species with markings of a darker tint, suggest a t first sight the result of some direct influence of locality. 'When, however, we remember that Dabida is a mountain while Isipingo is on the coast, and that the same species and forms on mountains such as ICilinianjaro near Dabida: and on the coast near Isipingo bear markings of the deeper tint usual in E. Africa, the inadequacy of this interpretation becomes obvious and we are driven to the hypothesis that the paler tint appeared as an inherent variation in one species of Amauris and that, by the operation of natural selection, the same shade of colour was gained by the other members of the association, except, on Dabida, by the more wandering Hypolimnas. Dr. van Someren's new forms from Marsabit also support tliis interpretation, although here the local tint of the Amauris is probably, as already suggested, due to the effect of the Abyssinian A . steclwi. Further support is also provided by the following exhibit.

ABLY DARKENED IN MIMICRY OF A. ANSORGEI Z.M.Sh.-Prof. POULTON exhibited a series of three species of Amaimis taken by Mr. H. L. Andrewes in 1920 and 1921 a t Lumbwa (7000 ft.), near the summit of the slope leading to the top of the Mau E.+carpment, forming the western boundary of the Rift Valley in Kenya Colony. In one species, Amauris nnsoyei, the hind- wing patch was exceedingly dark brown, and the forc-wing spots white, the effect being striking and highly characteristic. Of the two other species in the sn&e locality A . albimaculata had the patch much darker than the normal tint and A . echeria very slightly darker. These results were of remarkable interest when compared with tliosr discovered by Dr. S. A. Neave and

THE HIND-WING PATCH OF AMAURIS ALBIMACULATA PROB-

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published in Trans. Ent. SOC., 1906 (pp. 208-210, pl. IX). Dr. Neave showed that in Uganda the two last-named spegies were modified in mimicry of the dominant Aiizauris psythleu f . damoclides Staud. and that here too albirnaczrlata-very rare as compared with echeria-was a closer niiniic than echeria. But whereas in Uganda west of the Victoria Nyanza mimicry had meant (in addition to changes in the size and form of the spot in the forewing cell) increased paleiless of the hind-wing patch in mimicry of a black-and-white Amauris,* a t Lumbwa, with a differeiib model, it had meant increased darkness. Dr. Neave had also shown that the mirnetic approach of both albimmzilata and echeria was closer in the female than the male ; but this result could not be compared with Lumbwa, for all Mr. hndrewes' specimens happened to be males.

The following analysis of the t h e e Awauris from Lumbwa, with two of their Pccpilio mimics, in Rlr. Andrewes' collection clearly showed that the species flew together :-

Lurnbws, Kenya Col . 7000 fL.

-____ 1!)20, June

Aftinurns msrrrpi . Males.

~~

L921, Mar.

,, April

Totals 1 10

* There is reason to believe that the oomdon Uganda form of A. psyttalea Plotz may have been reciprocally influenced by the two other species, for its hind-wing patch is often of a faint but quite distinct yellowish tinge. The comparison of large numbers from other areas is required in order to test this conclusion.

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Neither of the mimetic female Papilios was darker than is usual in East Africa. Although in the table the numbers of the three Amauris were nearly equal, Mr. Andrewes remem- bered that ansorgei was much rarer than the other two. Its effect, in spite of its numbers, on albimaculata was probably due to the variability of the mimic and the striking pattern of the model. Similarly a t Chirinda (S.E. Rhodesia) the hippocoon female of dardanus, with a relatively uncommon but extremely conspicuous niodcl, Ainaiiris niavius donzini- canus, was far more abundant than the cenea female with its much commoner but less conspicuous models, Amauris loben- yula and A . albimacdata; also than the trophonius female which only commonly meets its abundant and conspicuous model Dunaida chrysippus L., on the overlapping borders of their respective stations.

The probable effect of ansorgei upon albinaaculata was suggested several years ago by the specimens kindly presented to the Hope Department by Canon Rogers. These included a fine series of aiuorgei from Narasha, fifteen miles north of Londiani, near Lumbwa ; but the number of albimaculata was insufficient to carry conviction. Confirmation was now abundantly supplied by Mr. Andrewes’ collection.

Examples of albimacdata with a dark hind-wing patch similar to that of the exhibited series existed in the British Museum collection from the following localities :-Nandi plateau (l), Lumbwa (I), Munisu (l), Kikuyu (2)) Roromo: Xikuyu (1). All except the last were males. Prom these and the larger series in the Hope Department it appeared evident that the effect of ansorgei extended for some, little distance both east and west beyond its localities on the Mau Range.

MIGRATION OF THE PIERINE BUTTERFLY BELENOIS MESEN-

TINA CRAM., ACROSS THE WIND AT NAIROBI, TOWARDS THE

END OF THE DRY SEASON.-Prof. POULTON brought forward the following communication by Canpn St. Aubyn Rogers. There was a t the present time muchbterest in the problems of butterfly migration, and it was important to record as many fresh observations as possible.

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“Nairobi , February 21, 1924.

“ We have had a very pronounced dry season this year, and had practically no rain from the first week in December up till the present week, and everything has been very dry and little doing in collecting as far as butterflies are concerned. We had very nice rain this week, three nights in succession, which was very welcome, as it has laid the dust and freshened up our gardens, but it seems to have settled in dry again now. The rains proper do not usually begin before the last week in March. There has been a migration for several days this month of Belenois nzesentina. It was not a very large migration, but both males and females were concerned. The migration was from N.W. to S.E., the wind being variable from N.E. so that the migration was right across the wind.

“ Generally migrations before the heavy rains are from some point between S.W. and S.E.”

FURTHER NOTES ON THE NOCTURNAL FLIGHT OF THE ETHIO-

said that Mr. Walter Feather had sent to hiin on June 26, 1923, the following note on the habits of this species. The accompanying specimens were dated June 21 and 22, 1923, and were taken a t Moa, on the coast, about 25 miles N. of Tanga, N.E. Tanganyika Territory :-‘‘ This Skipper comes to the flowers of the $. Papaw a t dusk and continues until quite dark; in fact I have taken them with a light three- quarters of an hour after sunset. They also come in the early morning before sunrise when quite dark. $1 have not yet noticed them at the flowers during the daytime, but a t dusk they are extremely active, rivalling the Hawk-moths in the rapidity of their movements.”

On October 2, 1923, Mr. Feather wrote again recording further observations, but had not succeeded in witnessing the display of the white-marked antennae of the male :-“ since your letter I have been observing the Skipper Ploetzia cerymica, and have seen a very few flying in t h e daytime. They appear to be fond of resting in shady places a t dusk. ’I have not so far seen any attempt a t courtship. The white antennae are certainly striking and must be of sonic special use.”

The first record of the nocturnal habits of this species was

PIAN HESPERID PLOETZIA CERYMICA HEw.-prof. POULTON

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due to Canon St. Aubyn Rogers (Ent. Monthly Mag., 1913, p. 130; Proc. Ent. SOP., 1918, p. xxvii), confirmed by Dr. G. D. H. Carpenter, who observed the brilliant effect of the glistening patch on the antennae of the male (Proc. Ent. SOC., 1915, p. xliv). There was a good deal of evidence, chiefly from the West Coast, which showed that the Hcsperid also flies by day (ibid., p. xlv).

THE CLOSE RESEMBLANCE BETWEEN TWO HISPID BEETLES

TAKEN ON THE SAME GRASS AT KUMAON, U.P., INDIA.-PlOf.

POULTON exhibited examples of Downesia sasthi Mlk., and D . gestroi Baly, to which his attention had been kindly directed by Mr. S. Maulik. The specimens were part of a scries of thirteen, collected by Mr. H. G. Champion in the sheaths of Thysanolnena agrostis Nees, a t Kumaon. T. qrost is was described as “ a large grass with broad bamboo-like leaves and dense panicles of very small flowers, found in shady places in the forests all over India ” (“ Manual of Indian Timbers,” J. S. Gamble, F.R.S., Lond., 1902, p. 742). The proportions of the beetles were 9 sasthi to 4 gestroi. The simple colour-pattern was that commonly found in Oriental Lycidae-red-brown ahtcriorly, black posteriorly-and it would be interesting to know whether these Hispidae associated with Lycidae. There could be little doubt, however, that flower-haunting beetles of this latter group were common in the same areas, and provided an effective advertisement of distastefulness. Mr. Maulik had informed him that the same colours and pattern are found in other species of Downesia from widely separated localities in India and Ceylon. Further- more, the late Mr. R. Shelford included a I-Iispid beetle, G‘onophora wallacei Baly, of which one form had the above- mentioned pattern while the other was entirely red, in the two associations centred by Lycid beetles in Borneo (P.Z.S., 1902, pp. 267-269, pl. XXIII, figs. 15 and 27).

AN ABERRATION OF ARGYNNIS SELENE.--H. M. EDELSTEN exhibited an aberration of Argynnis seleiae from Sussex with the usual brown markings on the inner portion of thc underside of the hind-wings replaced by black.

PROC. ENT. SOC. LOND., I, 11. 1924. C