HENRY J. FRANKLIN. 375 



Variation. — The principal variation of this species has 

 already been noted in the above description, viz., the varia- 

 tion in the coloration of the pile on the first and second dor- 

 sal abdominal segments. The type specimen of centralis 

 represents the extreme dark variation in the coloration of 

 these segments, and it has so much dark pile on the middle 

 of these segments that I consider it something of an aberra- 

 tion. Cresson's juxtus represents the extreme yellow varia- 

 tion in the coloration of these variable segments. I cannot 

 believe that Cresson's centralis and juxt^is represent two 

 distinct species as I find them grading completely into each 

 other. I do not even consider them distinct subspecies. 

 They might have properly been described as color variants 

 of the same species, but I have seen fit to include the whole 

 line of variation in the main description of the species. 



Habitat. — I have records of this species from British 

 Columbia, Washington, Idaho, western Montana, Oregon, 

 Wyoming, California, Nevada, Utah, Colorado, Arizona, New 

 Mexico (Cloudcroft, Magdalena Mountains, Beulah, Monu- 

 ment Rock, top of range below Sapello and Pecos rivers) 

 and western Nebraska. Is it present in western Kansas, 

 western Oklahoma, northwestern Texas, eastern Montana, 

 the western Dakotas and Assiniboia ? It is mainly a Transi- 

 tion species, but it runs over somewhat into the Boreal 

 Region on the one side and the upper Austral Zone on the 

 other. It is a common species throughout a considerable 

 portion of its habitat. What are its northern and southern 

 limits ? Does it range into Mexico ? The record, given by 

 Titus {vide supra), of a male of this species from Woods 

 Hole, Mass., is absolutely erroneous. 



This species is most closely allied to B. flavifrons Cress., 

 from which it can be separated by the somewhat shorter 

 malar space of its females and by the more distinct and 

 definite black interalar band of both sexes. It also re- 

 sembles the color variant of pleia'alis quite closely, but its 

 face is largely covered with yellow pile and its black inter- 

 alar band is noticeably narrower than that of pieuralis, at 

 least in the females. 



TRANS. AM. KNT. SOC. , XXX VIII. 



