152 U- S. NATIONAL MUSEUM BULLETIN 216 part 3 



eel light brown, fuscous above; flagellum dark brown or blackish, with 

 a broad white band; propleurum black or partly whitish; pronotum 

 black, its front, lower, and upper edges broadly margined mth white ; 

 tegula white; mesoscutum black or brownish ferruginous, with or 

 without a median white spot; scutellum and postscutellum white, 

 surrounded by black; sub tegular ridge and often a stripe below ster- 

 naulus, white; rest of thorax fulvous; front and middle legs fulvous, 

 their tarsi brownish apically and their coxae and trochanters more or 

 less white; hind leg fulvous, the apex of its tibia a little darkened, its 

 tarsus with second, third, more or less of apical part of first, and more 

 or less of fourth segment, ivory; abdomen fulvoferruginous, its apex 

 darkened, sometimes the fifth and following tergites black. 



In the AUeghanian fauna this subspecies is rather constant and 

 characteristic in color and structure. In the Canadian zone of the 

 East, specimens tend toward the subspecies pedoralis, but nearly all 

 from the eastern half of the continent are classified as atricollaris . 

 Farther west, most of the specimens come under the definition of pec- 

 ioralis, but even to the west coast of British Columbia there are some 

 specimens with the characteristics of atricollaris. The zone of in- 

 tergradation continues southward along the Rocky Mountains to 

 New Mexico, narrower than in the north. We caught series containing 

 representatives of both forms (but typical of neither) at Steamboat 

 Springs, Colo. These and other specimens from Colorado show 

 some tendencies in the direction of the subspecies atriceps, and a 

 male from Morley, Colo., agrees entirely with the definition of atri- 

 ceps. A female collected with this male is classified as atricollaris, 

 but if its tegula were fulvous rather than white it would pass for an 

 atypical atriceps. These are illustrations of the difficulty of drawing 

 definite boundaries between our four American subspecies. 



Specimens (229 c?', 3789): From British Columbia (Canim Lake, 

 Likely, and Wilham Lake) ; Colorado (near Estes Park, Fort Collins, 

 Glen Haven, Grand Lake, Granite Peak Camp near Bayfield at 

 9,000 ft., La Poudre River near Indian Meadows, Lyons, Mill Gulch 

 in Jefferson Co., Morley, Poudre Canyon west of Fort Colhns, and 

 Steamboat Springs); IlHnois; Maine (Bar Harbor, near Bethel, 

 Casco, Clayton Lake, Echo Lake on Mount Desert, Fort Kent, 

 Monroe, Moose Head Lake near Greenville, Pittston, Rangeley, 

 and Stratton); Massachusetts (Forest Hills, Holhston, Maiden, 

 Monterey, and Riverside); Michigan (Alger Co., Alston, Alto, Ann 

 Arbor, Antrim Co., Atlanta, Baraga Co., Benzie Co., Brevort, Che- 

 boygan Co., Clare Co., Crawford Co., Delta Co., Drummond Island, 

 East Lansing, Floodwood in Schoolcraft Co., Gladwin Co., Gogebic 

 Co., Houghton Lake in Roscommon Co., Huron Co., Huron Mts., 

 Iron Co., Isabella Co., Isle Royale, Keweenaw Co., Lake Co., Mack- 



