New Forms of the Genus Delias (Pieridae) 317 



4. The red band further reduced, with only slight scaling at bases 

 of cellules 3, 5, 6, and none in 4. Nomnagihe, 2,000 feet, January and 

 February, two 3 $ . 



5. The red band still further reduced proximally and posteriorly. 

 Wanggar, February, one 3" . 



6. The red band indicated by scattered scales in lc, base of 2 

 and end of cell. Fore wing with white inner margin but slightly ex- 

 tending beyond submedian. Red subbasal spot as in irma. Nomnagihe, 

 one cf . 



Three 2 ? are to be noticed. These have the upperside as in irma 

 but paler yellow and with a very pale-yellow and sharply denned 

 cellspot. 



1. Underside. Fore wing with cellspot as above and a submarginal 

 row of seven pale yellow spots. These spots occur in some of the 

 typical females, but in these they are white. Hind wing with the 

 discal yellow scaling accentuated on the middle of the discocellulars, 

 and distally indicating the outer edge of the band found in the typical 

 form. Wanggar, February, one. 



2. Fore wing with submarginal spots less well-defined than in 1. 

 Hind wing with a discocellular yellowish-white mark and a few yellow 

 scales surrounding it. 



Wanggar River, 15 miles inland ca. 600 feet, January, one. 



3. Typical irma except that the fore wing spot is yellowish-white 

 and the hind wing with a slight yellow discocellular mark. 



Nomnagihe, 2,000 feet, January to February, one. 



The most widely distributed form is aruna, occurring in Central 

 (late German) New Guinea, Dutch New Guinea, Waigeu, Roon Island 

 and the North Moluccas. The other form, inferna Butl., occurs in 

 the Snow Mountains in British New Guinea {irma Fruh.) and Cape 

 York. 



It may be supposed that aruna is the earlier form and that the 

 later tendency was to the reduction of red, a tendency which became 

 more definite as the range of the species increased southward. This 

 tendency is probably seen in Roon Island specimens {rona Roths.), in 

 which the red is suffused with black, and also in the specimen from 

 Geelvink Bay which we have described. 



Intergrades should also be found further south, where also at present 

 only aruna is known. 



Both are coast forms and their distribution is limited by the 

 high land. 

 21 



