on Eastern Butterjiies . 



34-1 



List of the species of Terinos. 

 1. Clarissa, Boisd. Sp. Gen. pi. ix. f. 4. 



2. Nympha, Wall. 



3. Rohertsia, Butl. 



4. Viola, Wall. 



5. Terpander, Hewits. 



6. Taxiles, Hewits. 



7. Abisares, F eld. 



8. Tewthras, Hewits. 



9. Tethys, Hewits. 



infrA, p. 342. 



Ann. Nat. Hist. 3rd 

 Ser. XX. pi. viii. f . 2-4. 

 infra, p. 343. 



Java, Borneo, Singa- 

 pore (W.). 

 Borneo (W.). 



Malacca, Siiniatra(W.). 



Singapore, Sumatra 



(W.). 

 Borneo. 



Batchian, Gilolo (W.). 

 Celebes (W.). 

 East India. 



Proc. Zool. Soc. 1862, 



p. 90. 

 I. c. p. 89, pi. X. f. 3, 4. 

 Nov. Voy. p. 886. 

 Proc. Zool. Soc. 1862, 



p. 89. I 



I. c. p. 88, pi. X. f. 1, 2. ' Mysol (W.). 



The most striking characteristics of these insects are 

 the hairy eyeSj and the large plush-like scales which, in 

 the males, form a large patch on both wings, but which 

 are often replaced in the females by blue bands and 

 patches, giving this sex the aspect of a distinct species. 

 Still more remarkable, however, is the great difference 

 of neuration presented by the sexes in some of the 

 species. Mr. Hewitson pointed out the variation in the 

 position of the lower disco-cellular vein in relation to the 

 second branch of the median vein, whereby closely allied 

 species may readily be distinguished. This is undoubtedly 

 the case ; but by examination of four species of which I 

 possess both sexes, I find that the difference between 

 the neuration of the sexes is fully as great as between 

 that of the most distant species. I find also by measure- 

 ment and comparison, that the disco-cellular vein retains 

 a constant position, so that the length of the cell does 

 not vary, and that it is the branches of the median vein 

 that alter their position, being, in some cases, very much 

 further from the base of the wing than in others. In T. 

 Clarissa the sexual difference is perceptible, but slight. 

 In T. Eohertsia and T. Taxiles it is very easily seen, as in 

 the male the second median branch springs from the 

 same point as the lower disco-cellular, while in the female 

 it comes almost exactly midway between the first and 

 second branch. In T. Ahisares the difference is still 

 more marked, since in the male the disco- cellular arises 

 in advance of the second median branch, while in the 

 female it is nearly midway between them. This is a re- 

 markable illustration of Darwin's law, that when a parti- 

 cular character varies sexually, it also varies specifically. 

 As a rule, differences of neuration are generic, rarely 



