THE CANADIAN ENTOMOLOGIST. 39 



Second segment orange red, face pale, black hairs above 



antenna? sylvicola. 



Second segment with basal middle yellow rufocinctus. 



CC. Scutellum and second segment partly black, remainder of 



second segment orange-red bifarius. 



BB. First two segments yellow, third and fourth orange-red. 



Scutellum all yellow juxtus. 



Scutellum partly black, thorax anteriorly mixed with 



black flavifrons. 



AA. Apex of abdomen not entirely black. 



Apex of abdomen orange-red, first two segments yellow, third 



black Oregonensis, $ . 



Apex of abdomen not so bright, some yellow mixed with fulvous 

 colour . . Couperii. 



Dorsum of thorax with mixed pubescence. 



First two segments pale, third black, apex orange-red mixtus. 



All localities in the following list are in Colorado, except where 

 otherwise stated. 



B. dorsalis, Cress., 1878. 



Mr. Ashmead, in looking over my table, has written in " First 



segment yellow, 2, 3 and 4 fulvous dorsalis, $ ." I have not 



seen the specimens the note was upon. 

 B. separatus, Cress., 1863. 



? June, $ July 20, August 8 (C. Stannard) at Ft. Collins: $ 

 Henderson, August 30 (Gillette). 



B. Morrisonii t Cress., 1878. 



9 May 10, June S, 9, September 15; $ July 20, 24; <$ September 

 22, at Ft. Collins. 2 ? July 13, Trinidad; August 5, Antonito 

 (Gillette). ? £ August 21, Cerro Summit; August 19, Horsetooth 

 Gulch. g August 22, Cimmaron. Taken on Cleomc semt/ata, 

 Mentzdia mu/tijlora, Heliatithus annuus, T/icrmopsis montanum, Alnus 

 viridis and " wild rose." 



This very distinct species is one of the largest and finest Colorado 

 Bombidaj ; and is found not uncommonly in Colorado and New Mexico. 

 B. pcrplexus, Cress., 1863. 



One J September 22, Ft. Collins, which I doubtfully refer to this 

 species, The pubescence is beautifully bright, and the black hairs are 



