(66 Miscellaneous. 



In the fuscous-black male of P. Castor the fore wing may be said 

 to be uniform black, the incisural spots, which alone remain, being 

 80 reduced in size as to be barely visible, beiug, in fact, mere specks 

 confined to the fringe ; the hind wing has lost all but the incisural 

 specks (which are similarly confined to the fringe) and the first three 

 or four spots of the discal series, which together form a large and 

 conspicuous cream-coloured blotch divided by the veins. P. Castor 

 may, in fact, be described as a rich dead-black insect with a con- 

 spicuous cream-coloured blotch near the outer angle of each hind 

 wing. 



In P. Castor, then, the sexes are, as regards colour and markings, 

 as strongly differentiated from one another as in any species with 

 which I am acquainted ; they also difi'er to some extent in form, 

 the male having the fore wing narrower, with the external margin 

 obviously emarginate, and the hind wing also narrower and pro- 

 duced, with the same margin more deeply incised and lobed than in 

 the female, both pairs of whose wings in form more or less closely * 

 resemble those of both sexes in the other two species. 



In P. Ilahadeva the sexes are also tolerably well, though not so 

 conspicuously, diff'erentiated in point of colour and markings as in 

 P. Castor, but not at all in form, the wings being of the same shape 

 in both sexes. 



In- P. Dravidarum the sexes agree perfectly both in form of wings 

 and markings, differing verj' slightly in colour only ; so that but 

 little sexual diff'erentiation has here taken place. 



The female of P. Dravidarum is scarcely distinguishable, as far as 

 one can tell from a description alone, from that of P. Mahadeva, the 

 only differences that I can make out being that in the latter " the 

 fore wings have very small and less distinct submarginal white 

 spots, and no spot at the end of the cell." From that of P. Castor, how- 

 ever, it is readily distinguished by having, as I have already pointed 

 out, the discal markings of the hind wing in the form of a transverse 

 band of short lanceolate spots. 



At the meeting of the Linnean Society of London held on the 

 18th March last, a paper by Prof. Westwood on a supposed poly- 

 morphic butterfly from India was read. In this memoir the follow- 

 ing conclusions are said {vide abstract in 'Nature,' vol. xxi. p. 531, 

 April 1st, 1880) to have been arrived at by the author:— "(1) 

 That Papilio Castor is the male of a species whose females have not 

 jet been discovered ; (2) that the typical P. Pollux are females, of 

 which the males (with rounded hind wings having a diffused row of 

 markings) have yet to be discovered ; and (3) that the coloured figures 

 given by the author represent the two sexes of a dimorphic form of 

 the species." 



With regard to the last of these conclusions [ cannot speak, be- 

 cause neither the paintings nor the specimens in question are acces- 



* The females present an inconspicuous dimorphism, some having 

 retained the primordial form of hind wing, while others have the outer 

 margin of this wing toothed as in the male {t'ide infra). 



