1955] 
Wilson and Brown — Formica 
113 
(1) In habitus of all castes of both sexes, and in details 
of worker-queen sculpture, pilosity, and form of propodeum 
and petiole, members of the obtusopilosa complex and the 
Nearctic species of “Proformica” ( neogagates group) are 
obviously similar. 
(2) The diagnostic Proformica character involving pro- 
portions of the first three funicular segments, never a 
very happy distinction, appears to grade through in the 
sanguinea-obtusopilosa series. 
(3) The clypeal notch, supposedly characteristic of 
Raptiformica, is as well (or better) developed in many 
F. neogagates specimens as it is in those of some species 
customarily placed in Raptiformica (e. g. bradleyi, or even 
subnuda). The notch in neogagates and bradleyi is more 
properly described as a “vaulting” of the median clypeal 
margin as seen from an adoral view, but the effect is the 
same from full-face view, and the difference from tne 
condition of subnuda is trifling, not to say academic. In 
neogagates, which appears to be a species distinct from 
bradleyi (= morbida ) on the basis of color and pilosity 
characters, variation in clypeal vaulting is considerable. 
Most western samples show stronger vaulting, frequently 
equalling bradleyi, while some eastern samples have a flat- 
tened border like that of lasioides. 
(4) The parameres and subgenital plate of the male in 
neogagates, bradleyi, and perpilosa are very similar (see 
figs. 4, 6). 
(5) Many of the Palaearctic species of Pro formica, in- 
cluding the subgeneritype F. nasuta Nylander, differ 
markedly from the Nearctic species (typified by neoga- 
gates) in characters involving degree of worker poly- 
morphism, and in worker-queen mandibular dentition. In 
addition, the male genitalia are very distinctive in the 
one species, nasuta, in which males have been examined. 
These species seem to form a monophyletic group easily 
separated from the Nearctic neogagates group as well as 
from all Nearctic Formica. 
Conclusions drawn from these facts are: (1) the obtu- 
