( Ivii ) 



of a genus, or of a definite Structure-group within the 

 genus, were found in different Colour-groups in the different 

 islands, and sometimes even within the limits of a single 

 island. 



Although the species of OJynerus were the dominant 

 members, some of the Colour-groups also contained bees, of 

 which the 53 species in the single genus iVesoproso2ns, were 

 traced to a probable single Asiatic immigrant, allied to 

 Prosopis li'neclihauineri, FiJrst ; and Fossores (Crabronidae), of 

 which the 18 species and 3 genera were believed to have arisen 

 from a single Asiatic invader, allied to Crahro vagus, L. The 

 main Colour-group also included Ichneumonids. 



In illustration of the paper, Prof. Poulton exhibited the 

 specimens referred to in the following letters written to him 

 by Dr. Perkins, Nov. 2 and Nov. 4, 1911, but here combined. 

 Tlie Colour-groups were arranged in the order of the islands, 

 from Kauai in the N. W. to Hawaii in the S.E. The avithors' 

 names had been added by Prof. Poulton. 



" Herewith I am sending a small box of Hawaiian Hymeno- 

 ptera, showing the main colour-effects.* 



"Colour-group A [= II of Kauai in Dr. Perkins's memoir.] 

 — Black, wings dark, blue reflections, two white or yellow 

 bands, second always broad. The examples selected are : — 



Odynerus kirbyi, Dalla Torre .... Kauai. 

 Nesodyneri(,s vittativentris, Perkins . . . Kauai. 



" All the Kauai species, whether open country or forest insects, 

 belong to this group, excepting one or two apparently recent 

 arrivals from other Hawaiian islands, which are only slightly 

 different in structure and appearance from Odynerus sand- 

 wichensis, de Sauss., of Group D. 



"Group A is not exactly represented on the other islands, 

 but a sub-group of pale-banded species on Oahu approaches 

 it, and it is curious that the insects so coloured on all the 

 islands except Kauai belong to the lowlands (open), or to the 

 open country above the forest line, or to open spaces in forest 



* Dr. Perkins wrote Nov. 13, 1911 : — "Tlie characteristic appearance of 

 the various groups is far more remarkable in masses of specimens, sucli as 

 I liave in my cabinet drawers, than in a few isolated specimens." 



