fe 
Specific Characters in the Bee Genus Colletes 57 
cotypes antedates thé description of the Kansas specimen eight 
months, at 
Specimens from the Transition and Canadian life zones of 
New Mexico, Arizona, and Colorado differ from eastern speci- 
mens in a’ usually stouter and shorter prothoracic spine in the 
female, and such specimens form the basis of C. bigeloviae Ckll. 
and C. brevispinosus Viereck, typical specimens of which I have 
had the opportunity of studying. The difference is so slight and 
nureliable, however, that it seems to me unwise to consider them 
as distinct in any way. Certain it is that the characters ascribed 
to bigeloviae in the original description, viz., dark flagellum, 
dark tegulae, smoky wings, etc., have no value whatever in the 
separation of species in this genus. The Mesilla valley specimen 
with which bigeloviae was compared represents the other ex- 
treme of variation in this species, as does also the male described 
from western Kansas by Patton, and indeed as is shown in most 
of the specimens from the Upper Sonoran hfe zone. A large 
series of armatus from Nebraska, in which both sexes are well 
represented, shows variations from the usual eastern form which 
seem clearly attributable to the dryer climatic conditions. The 
pubescence is much paler, there being fewer black hairs on the 
thoracic margins of the female, especially anteriorly, and less of 
an ochraceous tinge on the face and mat on tubercles, while the 
pubescence of the male is all dull grayish white, not at all tinged 
with ochreous and entirely without black hairs on either the 
thorax or vertex; the wings of both sexes perfectly clear with 
testaceous nervures and the tegulae usually testaceous also. 
Again, three females from Atlanta, Georgia, have the wings 
heavily darkened and their nervures deep black, while the ab- 
domen is more shining and finely punctured, differing entirely 
from any specimen of armatus from the northern states, although 
Mr. Robertson, who examined a specimen, remarked that he had 
specimens just like it from southern Illinois. This variation will 
probably be found characteristic of the Lower Austral zone. A 
careful study of armatus convinces me that we have here to deal 
with a wide-ranging, quite variable species in the act of splitting 
up into several different forms, which are as yet so feebly and 
eat gata 
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