250 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iii 



The pallidipennis group is quite homogeneous, and although in 

 some respects it seems to be more primitive than the colei group, it is 

 certainly far more catholic in its adaptability. For example, there 

 are as many species of the colei group in New Zealand as in all of the 

 Nearctic region. A possible explanation for this might be that since 

 the pallidipennis group is represented commonly in the latter region 

 by no less than eight species, but is absent in New Zealand, there 

 would appear to be no competition there, and thus the members of 

 the colei group are not uncommon; whereas, in the Nearctic region, 

 members of the latter group are extremely rare, while those of the 

 pallidipennis group are the most abundant. It might be inferred 

 that competition for the same hosts (as pointed out earlier in the 

 biology section) among the various species of Ogcodes is one of the 

 major factors in the "rareness" of some of the species. 



It seems quite probable that some member of the colei group 

 (possibly vittisternum Sabrosky) gave rise to albiventris (Johnson), 

 which is now the monotype of the Nearctic subgenus Neogcodes. 

 The porteri group remains a spurious one at present but is apparently 

 most closely related to species of the eugonatus group. 



Group I — brunneus group 



Diagnosis: Veins Mj, M2, M4, Cu2, A, and crossveins m-cu and r-m 

 present (pi. 3, fig. 8) ; median plate of ejaculatory apodeme either 

 expanded basally (pi. 11, fig. 75) or not; basal cell of apodeme round, 

 incomplete ventraUy; apodemal wings short and median plate of 

 medium size (pi. 12, fig. 83) ; aedeagus somewhat narrowed or broad- 

 ened at apex, with small or no postgonoporal notch; body pile rather 

 even and not extremely long; terminal antennal segment with one to 

 three small apical setae; abdomen with typical fasciae on tergites 

 (pi. 5, fig. 29). 



Included species: 0. brunneus (Hutton) and consimilis Brunetti. 



Group II — eugonatus group 



Diagnosis: Vein Mi absent, except sometimes faintly visible at 

 apex; crossvein m-cu absent (pi. 4, figs. 18, 19); ejaculatory apodeme 

 with short wmgs and incomplete basal and subbasal ceUs (pi. 11, fig. 

 78) ; median plate in lateral view narrow, nearly equi-breadth, directed 

 anteriorly (pi. 12, figs. 91, 93, 94); aedeagus blunt apically, flat sub- 

 apically, without postgonoporal notch (pi. 10, fig. 69; pi. 11, figs. 71, 

 73) ; apex of antenna usually with one seta; body pUe of medium length 

 and quite even; abdomen fasciated (pi. 5, fig. 29) or sometimes pat- 

 terned. This group was partly defined by Sabrosky (1948, p. 410) as 

 "#3, eugonatus complex." 



