392 AMERICAN HYMENOPTKRA. 



Bimensions .—Liength : queen, 15 mm. to 21 mm. ; worker, 8 mm. 

 to 15 mm.; male, 10 mm. to 16 mm. Spread of wings: queen, 37 

 ram. to 41 mm. ; worker, 17 mm. to 35 mm. ; male, 25 mm. to 33 mm. 

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

 worker, 3| mm. to 8 mm. ; male, 6 mm. to 8 mm. 



Each sex described from a large number of specimens. 



Variation. — Besides the typical species above described, 

 there is the following : 



Subspecies 1. — {dorsalis Cress, and aztecus Ckll.). Queen, 

 worker and male with dorsum of thorax completely covered 

 with yellow pile, no black interalar band being present ; 

 sixth dorsal abdominal segment of male often entirely yellow. 



The typical fervidus grades completely into this form. I 

 have examined the genitalia of the males and they are like 

 those of the typical form. This subspecies is found most 

 abundantly in the western United States, but it also occurs 

 rarely in the East. I have over thirty specimens of this 

 form before me, two of them homotypes. 



Habitat. — This species is present throughout all the states 

 of the United States, except as follows : Florida, Louisiana, 

 Alabama, Mississippi, the greater part of Texas, the eastern 

 half of Oklahoma, the greater part of Arkansas, the greater 

 part of Georgia, the eastern half of North and South Caro- 

 lina, eastern Virginia and the western portions of Tennessee 

 and Kentucky. I have records of it also from Canada as 

 follows : Ontario, Alberta (McLeod), Saskatchewan (the old 

 territory) and the old territory of Assiniboia (Regina). It 

 is also almost certainly present in Manitoba. Is it present 

 in southern Quebec and in New Brunswick ? Bowles has 

 recorded it from Montreal. What are its northern limits ? 

 Does it range into northern Mexico at all and, if so, how 

 far ? The species seems to be confined mainly to the Transi- 

 tion and Upper Austral Zones, but it runs over somewhat 

 into the Boreal Region. It appears to be the most common 

 species throughout a good portion of the New England, 

 Middle Atlantic and Central States, but much less abundant 

 in the Pacific States. Dr. Davidson states that it is "the 

 most common of all the bumble-bees in the vicinity of Los 

 Angeles," Cal. He states further that it is most abundant 



