306 Dr. Frederick A. Dixey on the 
the dark-coloured costa ; in others (as H. lalage) this has 
become a distinct discoidal spot, (Fig. 11). Hiposcritia, 
by its anal tufts, belongs decidedly to the Catophaga and 
Appias group; but the shape of its wings and the occa- 
sional persistence of dark ground-colour about the disco- 
cellular nervules indicate that its origin is to be placed 
somewhat far back towards Huphina and Metaporia. 
Starting again from Metaporia and Pontia, we find in the 
small Siberian P. lewcodice an unmistakable link between 
these genera and Synchloe. In S. callidice, which per- 
haps come nearest to Pontia, the female shows S and M 
in a well-defined condition, together with a large distinct 
discoidal patch; the nervures and nervules are also in 
many instances clothed with black scales. From S. 
callidice we can advance in one direction through 
S. chloridice to 8. glauconome, S. johnstonii, and 8. 
hellica ; while S. daplidice and its immediate allies form 
another slightly divergent branch from WS. chloridice. 
S. callidice again in all probability marks the point at 
or near which the assemblage of species grouped as 
Ganoris leave the main Synchloe stem; G. napi being no 
doubt the species which is closest to the original stock, 
as is shown by the large persistence of S and M, the 
tendency towards blackening of the nervures, the 
occasional indication of a discoidal spot, and the peculiar 
coloration of the underside of the hindwings. It is 
noticeable that Ganoris generally, including G. napi, 
retains the precostal yellow streak, which, though 
present in most species of Synchloe, happens to be 
absent in S. callidice. 
Most species of the genus Tatochilu strongly resemble 
Pontia in pattern (the resemblance between Tatochila 
and P. lewcodice has been pointed out by Mr. Butler, 
Proc. Zool. Soc., 1872, p. 62), while 7’. autodice 9 comes 
nearer to MW. agathon than does any species of Synchloe. 
The whole neuration of Tatochila is very similar to that 
of Pontia; and even the peculiar arching of the Ist 
subcostal of the hindwing (well seen in P. cratzgi) is a 
noticeable feature in 7. theodice and other members of 
the same genus.* Tutochila may, therefore, be considered 
to be a derivative from the Pontia stem at a point some- 
what further back than the existing species of Synchloe. 
* See Mr. Butler’s figures in Cist. Entom.,vol.1., pl. i1., figs, 7 and 9. 
