304 THE CANADIAN ENTOMOLOGIST. 



DD. With six bands radiatus, Say. ^ . 



CC. With white hair-bands viridulus, Fab. $ . 



BB. Abdomen honey-yellow melliventris, Cress. 5 . 



BBB. Abdomen yellow, with very narrow black 



bands melliventris, Cress. ,^ . 



The males of radiatus, Texanus and viridulus are hard to satisfac- 

 torily separate. That portion of the table relating to them has been 

 formed almost wholly from a study of the excellent paper of Mr. Chas. 

 Robertson, North American Bees, Desc. and Syns.*, in connection with 

 the study of the males in the collection of the Colo. Agr'l College. 

 Specimens of male and female of radiatus, Texanus and viridulus were 

 sent to Mr. Robertson, who kindly looked them over and verified or, 

 where necessary, corrected my determinations. 



The following is a list of the specimens now in the College 

 collections : 



Agapostemon viridulus, Fab., 1793. 



Thirty-five females ; Trinidad, Ft. Collins and Poudre Canon. 

 Ten males ; Poudre Canon and Ft. Collins. 



Taken on Salix, Taraxicum, Geranium, Opuntia and several 

 Cruciferae. 

 Agapostemon radiatus, Say, 1837. 



Two females, Delta ; two males, Montrose and Salida (Gillette), and 



one male, Poudre Forks (Laura Armstrong). 

 Females taken on Salix. 

 Agapostemon Texanus, Cress., 1872. 



Seventy-four females ; Greeley, Lamar, Dolores, Trinidad, Ft. Col- 

 lins and Rist Canon. 

 Twenty males ; Julesburg (Ball), Greeley, Fort Collins and Rist 

 Canon. This species has been taken on Malvastrum coccinium, 

 Salix, Taraxicum, Geranium and Cnicus. 

 Agapostemon melliventris. Cress., 1874. 



One female at Delta, Colo., 27-V.-00, on Salix, by Prof. Gillette. 

 There are also in the collection a female taken in Mesilla Valley, 

 N. M., on Solanum, and a male from Las Cruces, N. M., on 

 Solidago, both from Prof Cockerell. 

 Colletes tiigrifrons, n. sp. $ . 



Length, 7-8 mm. Black, rather heavy set ; head broad, clypeus 



*Trans. Acad. Sc, St. Louis, VII., No. 14, 1897. 



