xxxiii, '22] ENTOMOLOGICAL NEWS 215 



that in the cold regions B, kirbyellus (Curtis) and B. liypcr- 

 borcus (Schonherr) in some instances apparently produce only 

 queens and males, a condition characteristic of solitary bees. 



B re ni us kincaidii is also interesting from a systematic stand- 

 point, as it belongs to a boreal group of bumblebees (Kirbyellus 

 Group Franklin) which presents many classificatory difficulties. 

 Franklin has suggested that this species may eventually prove 

 to be a "color variant or subspecies of strcnuiis or polaris." 

 Through the kindness of Mr. E. T. Cresson, Jr., the writer 

 has had the privilege of comparing Brcmns kincaidii with the 

 type specimens of Brcmns strcniius (Cress.) and a series of 

 Brcmns polaris (Curtis) contained in the collection of the 

 American Entomological Society at Philadelphia. 



As a result of this study I am forced to the conviction that 

 B. kincaidii, B. strcnuus and B. polaris are distinct species. 

 An examination of the genitalia of B. kincaidii bears out the 

 close relationship existing between all three species, particularly 

 its affinity with B. polaris. The inner spatha of B. kincaidii 

 has the general shape of the same structure in B. polaris as 

 delineated by Sladen (1919) and Franklin (1913). In the 

 specimen of B. kincaidii before me, the lateral margins of 

 the triangular-shaped apex of this structure are much straighter 

 than in B. polaris. In this last-named species, the lateral 

 margins of the triangular-shaped apex are inclined to be more 

 or less curved inward. The setae occurring on the inner spatha 

 are also more restricted to the tip and lateral margins of the 

 apex in B. kincaidii than in B. polaris. In B. polaris these 

 setae are more evenly distributed over the entire tip of the 

 triangular-shaped apex. Furthermore, in B. kincaidii the setae 

 do not extend to the two parallel, longitudinal lines or more 

 strongly chitinized areas, as is the case in B. polaris. The 

 claspers of B. polaris and B. kincaidii are almost identical. The 

 male of B. kincaidii collected by Dr. Hanna has the apical dorsal 

 abdominal segments predominantly black, whereas in B. polaris 

 these segments are normally ferruginous or have a large amount 

 of light-colored hairs. B. kincaidii is also less robust than B. 

 polaris, judging by the spc-cimens I have studied. 



An examination of the genitalia of the al'otype male of B. 



