442 AMERICAN HYMENOPTERA. 



and extending far beyond the tips of the squamae ; squamae with the 

 two lobes pointed and nearly equal. Sagittae with shafts bent outward 

 somewhat in the middle and heads very irregularly sickle-shaped, the 

 tips appearing narrow and pointed. Uncus very broad at base and 

 tapering somewhat rapidly to its rounded tip. 



Wiftgs. — About like those of the workers. 



Legs. — Coxae sometimes entirely black, but usually with some yellow 

 hair ; trochanters with more or less yellow pile on their lower sides ; 

 femora with considerable yellow hair ; fore and middle tibiae black ; 

 posterior tibiae with outer faces convex, naked and shining, with front 

 fringes short and black and hind fringes long and sometimes entirely 

 black, but often more or less strongly ferruginous. Posterior meta- 

 tarsi about two and one-half times as long as their greatest width ; 

 with moderately long hind fringes, sometimes black and sometimes 

 more or less ferruginous ; their outer faces concave and rather sparsely 

 pubescent. 



Dimensions. — Length: queen, 14 mm. to 16 mm. ; worker, 8 mm. 

 to 13 mm. ; male, 10 mm. to 15 mm. Spread of wings: queen, 31 

 mm. to 36 mm. ; worker, 18 mm. to 31 mm. ; male, 22 mm. to 31 mm. 

 Width of abdomen at second segment: queen, 8 mm. to 8| mm.; 

 worker, 4 mm. to 7 mm. ; male, 5^ mm. to 7 mm. 



Redescribed from fifteen queens (one of them a homo- 

 type of the edwardsii 9 of Cresson), ten workers and seven 

 males. 



Variations. — This species is the most variable in colora- 

 tion of any in the Western Hemispere. I here describe such 

 forms as seem marked distinctly enough to deserve descrip- 

 tion. Between these various forms (which I have chosen to 

 call Color Variants), I have seen almost every conceivable 

 gradation both in the males and in the females. I have also 

 examined the genitalia of the variously colored males and 

 find them to agree perfectly in every case. 



Color Variant 1 (var. albertensis Ckll.). — Queen and worker like the 

 typical form, but with abdomen entirely black except for the first and 

 basal middle of the second dorsal segments which are yellow. Three 

 queens and two workers from Montana (Bozeman and Gallatin County 

 — elevation about 5000 feet), one queen from Alberta (Calgary) and 

 one worker from the old territory of Assiniboia (Regina) . 



Color Variant 2. — The typical form of queen and worker described 

 above. Many specimens from Montana, Colorado and New Mexico. 



Color Variant 3. — Queen and worker like the typical form, but with 

 the apical portion of the third dorsal abdominal segment more or less 

 ferruginous and the fourth dorsal segment entirely yellow. Several 



