446 On a new Form of Delias from Rossel Island. 
Approximate dimensions (measured on skin) :— 
Head and body 340 mm. ; tail 90 ; hind foot 50. 
Hab. (of type). Bukit Gantang, Larut, Perak. 
Type. Adult male. B.M. no. 2.5.2.4. Presented by 
the Perak Museum. 
That this animal should be distinguishable from the related 
forms in Burma and South-eastern Siam is only natural, as its 
locality is so widely distant from theirs, down in the southern 
part of the Malay Peninsula. 
LI.—A new Form of Delias from Rossel Island. 
By J. J. Joicey, F.L.S., F.E.S., and G. Tatzor, F.E.S. 
Delias ornythion rosselana, subsp. un. 
3. The hind wing below has a thicker red line than in the 
typical form, and in some specimens it 1s twice as thick. 
?. This only differs in the more regular edge of the white 
area on the fore wing. ‘The red line on the hind wing tends 
to be thicker than in the male. 
Described from aseriesof 16 ¢ ¢,2 2 9, from Mt. Rossel, 
2100 ft., Rossel Island, Nov.-Dec. 1915 (W. F. Hichhorn). 
On Waigeu and throughout Dutch New Guinea is found 
the race Persephone, Stgr., with the completely black hind 
wing showing rarely a vestige of a red line. In German and 
British New Guinea as far east as St. Aignan occurs typical 
Ornythion with a complete red line on the hind wing, which 
is only rarely vestigial. Rossel Island is the farthest east of 
the Louisiade group, to which St. Aignan belongs, and here 
we find the tendency for the red line to increase in size. 
Two other Delias are known from this island—maga, 
Gr.-Sm., which is a race of mysis, Fbr., and irma, Fruh., 
being the Brit. N. Guinea race of aruna, Bdv. D. maga 
was described from Sudest Island, also one of the Louisiades, 
but the specimens from Rossel show a narrower black 
margin to the hind wing below as compared with the type. 
We refrain from differentiating this form in the absence of 
more material from ‘the typical locality, the ¢ type alone 
being represented in the collection. 
