( cxiii ) ' 



There is an important group of Delias, consisting of D. mysis, 

 I), argenthona, D. caeneus, and D. eucharis with the geo- 

 graphical forms D. stolUi, hierte and hyjxirete, which is marked 

 off from the rest of the genus no less by the character of its 

 plume-scales than by its obvious aspect. The laminae in these 

 species possess the common character of a triangle with elon- 

 gated apex, so that their outline may be compared to that of 

 an inverted funnel or trumpet. In D. argentliona and D. 

 hyparete, the lamina, fi*om its expanded and rounded base, 

 may perhaps more aptly be termed decanter-shaped. The 

 apex in these species, though narrow, is blunt, and not filiform 

 as in the majority of the species of Delias. It is often later- 

 ally bent, and may be slightly twisted. The jfimbi'iae, which 

 are rather short, are termino-lateral. The scent-scales in all 

 this group are very much smaller than those of most other 

 members of the genus ; the discs are large in proportion, 

 generally rounded, and in some species, notably D. caeneus, 

 well-displayed in consequence of the straightness of the 

 footstalk. 



As regards their scent-scales, Delias nigrina and D. ornytion 

 are in some ways transitional between the eucharis group and 

 the rest of the genus. Like the former, they have a triangular 

 lamina with a prolonged apex ; this, however, is acute though 

 not filiform. The lamina is much larger than in the eticharis 

 section, but still below the average size of the genus. A 

 curious feature in D. ornytion is the frequent presence, on 

 one lobe only of the somewhat cordate base, of a sharp spur 

 looking like a rudimentary form of such a spine as occurs in 

 " Ptychojyteryx " lucasii. 



It is perhaps worth noticing that when I was investigating 

 the genus Delias from the point of view of colour-patterns, I 

 was inclined to consider D. nigrina as a term in the series 

 leading through D. Juupalyce up to D. agani2)2)e. The evidence 

 of the scent-scales, without conti-adicting this, seems to in- 

 dicate an approach on the part of D. nigrina to the eucharis 

 group, as well as to that with which I formerly associated it ; 

 and seems also to show that its alBnity with D. ornytion is 

 closer still. 



Next on our list comes the neotropical genus Fereute. The 



PROC. ENT. see. LOND., V. 1909. H 



