HARDWICKE'S SCIENCE-GOSSIP. 



271 



NOTES ON INDIAN BUTTERFLIES. 



Tl/TELANITIS ISMENE (M. Bela). My recol- 



-L rJ- lection of the habitat of these insects is of a 



dark, thickly-shaded, gloomy Himalayan hill-slope, 



clad with oak {Quercus incana) and creel {Pinus lotigi- 



folia). 



On very hot days, they may be seen flying with a 

 short, jerky flight, in the shade of the trees, just 

 within the line of sunlight. On such days you are 

 as glad of the shade as the Melanitis ; and it is 

 curious, as you tread the forest path, to see it rise 

 suddenly at your feet and disappear as quickly 

 within a yard. On the wing, it is of course plainly 

 seen, except in very dark corners ; but the moment 

 it settles among the dry spikes of the pines, and the 

 brown, scanty vegetation, which struggles for bare 

 existence under these trees it is lost ; and it requires 

 much experience of its way and keen eyes to find 

 it — no small object either — lying within a foot or two 

 of the path. 



The genus Melanites mimics on the under side of 

 the wings many species of fungi : and this, with the 

 sober colouring of the upper side, increases the 

 difficulty of finding the insect amid the debris of the 

 forest. 



The under sides of this genus are in all the species 

 very variable ; scarcely two being'exactly alike, as in 

 other genera : and this may arise from the fact that 

 they mimic the fungus most common at the time and 

 place of their flight. 



Elymiiias itndularis. — One of the most ^curious 

 mimics known is the female of this species, which 

 bears a remarkable likeness to Danais chrysippus, 

 the larvoe of which feed on madar {Calotropis gigantea), 

 which makes them and the butterflies distasteful to 

 birds and other enemies, and, I believe, poisonous. In 

 a cabinet, mites will not injure D. chrysippus, though 

 they devour everything else in the drawer. The 

 mimicry in this case is remarkable, because the 

 structure of the two insects is very different, belong- 

 ing, as they do, to widely separated species and 

 genera : and undularis has much the appearance of a 

 rough drawing of chrysippus, made on a black board 

 simply to produce the general eff"ect to an unscientific 

 eye. Whilst the female of undularis is of the rich 

 chocolate brown of chrysippus, and has its white 

 markings, the male is nearly black, with a rich purple 

 submarginal, interrupted band ; there is absolutely 

 no resemblance between husband and wife, and the 

 mimicry would seem to be valuable in preserving the 

 eggs of the future brood from the ravages of 

 enemies. 



Kallima Hugeli mimics a dry oak leaf on its 

 under side. It is a gay, conspicuous butterfly, measur- 

 ing four^inches across, and no doubt owes its exist- 

 ence very often to its power of resembling a dead leaf 

 when it settles.' 



Fapilio govindra — or, as Moore has lately in describ- 



ing my collection called^the genus, Cadugoi'des — is a 

 mimic, both in form and pattern, of Caduga tytea, 

 Danais Sita of Kollar ; but I do not understand, in 

 this case, the value of the mimicry. 



John H. Hocking. 

 [Mr. Hocking has kindly shown us a number of 

 specimens of Melafiitis, The dark spots on the outer 

 wing-surfaces are differently grouped in almost every 

 specimen, and resemble the fungus melampsom now 

 to be seen on dead poplar leaves. — Ed. S.-G.^ 



WATER SNAILS; A STUDY OF POND 

 LIFE. 



TW^O points have struck me in perusing this 

 interesting paper, to which, as no one else has 

 done so, I would venture to draw attention. 



Firstly, with regard to the formation of the shell of 

 the snail, the author quotes the old belief that it 

 "consists of the upper layers of the mantle which 

 have been thrown off, after the cells have been filled 

 by a deposit of carbonate of lime." 



This, however, is now by no means universally ac- 

 cepted as a correct interpretation of the process. Pro- 

 fessor Huxley, in his article "Tegumentary Organs," 

 in Todd's " Cyclopaedia of Anatomy and Physiology," 

 vol. V. pp. 489-492, maintains that the shell is found 

 as an excretion from the surface of the epidermis, and 

 in this view he has the support of so high an authority 

 (were such needed) as Dr. Carpenter, " The Micro- 

 scope," 6th ed. p. 669. Moreover, an interesting 

 paper on this subject by MM. Louge and E. Mer 

 appeared in " Comptes Rendus," vol. xc. p. 882, of 

 which an abstract is given in the Journ. Royal Micro. 

 Soc. vol. iii. p. 417. 



The authors of this paper are enabled to show that 

 the different layers of the shell are produced by 

 different regions of the mantle, and as they describe 

 these parts and their functions very fully, this paper 

 is well worth the attention of all conchologists. 



In the second place, I am sorely perplexed by the 

 concluding sentence of the anonymous author, in 

 which, speaking of the development of the embryo 

 snail, he says, "It maybe interesting to note that 

 what is known as the 'foot' of the snail by the 

 embryonic development is really an under-lip,''^ (the 

 italics are his), nor do his figures make this state- 

 ment one whit more intelligible to me ; so I fear 

 that I must have overlooked, somewhere or other, 

 an important paper on the homology of the "foot" 

 in Gasteropoda. 



In the adult Lymneidse certainly the head seems 

 distinct enough from the foot, as may be seen from the 

 figures given in the author's own paper (fig. 51, 52, 

 p. 80), where the molluscs are represented as they 

 appear when crawling on the surface of the water ; 

 but even when climbing the glass of the aquarium, a 

 well-defined line across the under-surface just below 

 the mouth marks the junction of the two closely- 



