684 Mr. R. C. L. Perkins on the 



Group III. Insects with red thoracic or abdominal 

 markings, or both, the wings dark and with blue reflections. 



0. frater, Dalla Torre, monas, cephalostictus, naiadum, 

 temjye, dryas, potamophilus, microdemas, monobius, erythro- 

 stactes, montivagus, sandivichensis, de Sauss., petrobius, 

 deinogaster, Jwmoeog aster. 



On Hawaii there is a general tendency of the above 

 three groups to become fused into one large group, all 

 representing I on Oahu, and on Maui, Molokai and Lanai. 

 0. ohscicrepundatus, Blackb., and rubi^opustidatus, Blackb., 

 and one or two others may be recognised as obscure mem- 

 bers of Group III, of Maui, etc. 0. newelli, sociabilis, and 

 scoriaceus represent II.* 



Speaking generally of these groups, I find that in the 

 field, the members of each are easily enough distinguished. 

 There are, as might be expected, some cases of species that 

 are intermediate in appearance and might be placed in 

 either of two groups, but these are very few. On Kauai 

 Group II stands out remarkably from all others, since 

 nearly all the Kauai species belong to it, while it is only 

 approached in appearance by a few species in Group IV on 

 Oahu. The tendency of the species to become red- marked 

 on the three intermediate islands (Maui, etc.) is very 



* [At this point it is convenient to print Dr. Perkins' comments 

 on the abstract of this paper and the lists of specimens sent by him 

 for exhibition when it was read (Proceedings 1912, pp. Ivi-lxv). 

 Dr. Perkins arranged the specimens and wrote the lists in the midst 

 of the preparations for his departure from this country, and he had 

 no opportunity of revising the MSS. On his return to England he 

 wrote, September 17, 1912, stating that my footnotes on pp. Iviii, lix 

 are correct, and that N. pubescens, var. in B (p. Iviii), and N. fusci- 

 pennis in E (p. lix) should be transposed. He turthermore explained 

 that the common typical N. pubescens placed in E (lix) does not in 

 reality fit into any group on Hawaii. Dr. Perkins wrote : — 



" I suppose I sent a specimen for comparison with the rare blue- 

 winged form, which we should expect to be dominant, and if selective 

 processes were going on now, would surely become so, this being a 

 grand chance for natural selection to work upon. The rare variety 

 is the one that fits the colour-scheme of Hawaii, the very abundant 

 typical form does not." 



Concerning 0. mnlokaiensis, referred to in the footnote on p. lix, 

 Dr. Perkins remarked that " the female never has bands and is a 

 perfect representative of the dominant Colour-group (E = I). 0. molo- 

 kaiensis male may have two fairly good pale bands (as in II of 

 Molokai, etc. = IV. of Oahu), or one may be entirely obliterated and 

 the other faint."] 



