1881.] PROF. J. O. WESTWOOD ON INDIAN BUTTERFLIKS. 483 



winged females is in tlie Hopeian collection, from Assam ; and 

 although this vein is produced rather more strongly than in the 

 other darker specimens, yet the hind wings are clearly as round as 

 in the others, and an inspection of Mr. Wood-Mason's two figures 

 (pi. viii. fig. 2, and pi. ix. fig, 2) is surely sufficient to prove the 

 specific identity of the two insects. 



Of P. dravidariim Mr. Wood-Mason obtained a single specimen 

 of each sex ; this, however, is fully sufficient to show that the insect 

 figured by nie (Plate XLV. fig. 2) is either specifically distinct from 

 the females of P. pollux, or that it is a local and permanent variety of 

 that species peculiar to a more southern latitude, which may have 

 tended to intensify the dark colour of the wings, and to limit the 

 pale patches. Furthermore, Mr. Wood-Mason's descriptions and 

 figures fully confirm my opinion that the two insects represented in 

 my Plate XLV. are the two sexes of the same species or race, or geo- 

 graphical variety, as it may be considered. Here, then, we have the 

 two sexes identical ; and if (as I consider to be the case) the female 

 is so generally identical with the female P. pollux, I think we are 

 warranted in concluding that the real male of P. pollux has notyet been 

 discovered, and that when found it will closely resemble ihe female 

 both in the form of its wings, and in their characteristic suffused 

 markings. The common P. panope is a perfectly analogous case, in 

 which the two sexes of a species marked very like P. pollux are 

 identical. 



Mr. Wood-Mason adduces no sufficient proof that P. castor is the 

 legitimate male of P. pollux ; and I must be allowed to suggest that 

 the analogy of those Butterflies which have a large white blotch on 

 the hind wings placed as in P. castor, and in which the females have 

 the same marks on the hind wings as the males, is of greater weight 

 in determining the non-sexual identity of my two species than the 

 unproved opinions of the authors quoted in the beginning of this 

 paper ; whilst the express statement of M. Ch. Oberthiir that he 

 possesses a female identical with my male P. castor, is sufficient to 

 disprove the assertion of the specific identity of my two insects. It 

 would, as it seems to me, be as improbable as if a new species of 

 Vanessa, closely alllied to V. atalanta, of which both the sexes are 

 identical in colour, form, and markings, were discovered in which 

 the male resembled V. atalanta and the female V. to or F, poly- 

 chloros. 



The question has, moreover, been further complicated by the 

 occurrence of a singular gynandromorphous specimen o{ P. pollux, in 

 the collection of Mr. Semper of Altona, who has been so good as to 

 send me a photograph of it.' The upper surface of this specimen is 

 represented in Plate XLIV. fig. 5; and it has been described and figured 

 in the Entomol. Monatschr. of Vienna, vol. vii. p. 281, pi. six. The 

 specimen is for the most part a female of the ivxxe pollux type, to which 

 sex the wings belong, with the exception of the inner posterior portion 

 of the right fore wing and the outer angle and costal area of the right 

 hind wing, which portions are masculine. On comparing the shape of 

 the hind wings and the markings of the outer angle of the same wings 



