HENRY J. FRANKLIN. 207 



present on the anterior part of the dorsum of the thorax. It 

 is least often found on the legs (the very proximal ends per- 

 haps excepted), on the cheeks behind the eyes, on the venter 

 and on the apical abdominal segment. This color shows 

 considerable variation in shade between different species, 

 being whitish on some while on others it is deep golden. 

 On most species, however, this color is light, approaching 

 the color of straw. 



Next to white, ferruginous is the least prevalent color ex- 

 hibited by bumble-bee pile. This color is usually confined 

 mostly to the dorsum of the abdomen, being most often 

 present on the middle or the apical segments. The corbicu- 

 lar fringes are more or less ferruginous in many species. A 

 few species have a considerable amount of pile of this color 

 on the thorax {dahlbomii, ephippiatus, handlirschi, rubicun- 

 dus) . Two species {dahlbomii and rubicundus) even have a 

 large amount on the head. This color varies much in shade 

 not only between different species, but also, though to a less 

 extent, between individuals of the same species. The range 

 is from a shade approaching very near to pale yellow to an 

 almost cupreous color. 



White is the least prevalent of the general colors of bum- 

 ble-bee pile. As a rule, it is confined to the apical half of 

 the dorsum of the abdomen. A few species have it, to a 

 considerable extent, on the dorsum of the thorax (e. g. — 

 appositus and iunebris). White or whitish pile is noticeably 

 present on the head of appositus, borealis and edwardsii. Pile 

 of a gray or cinereous color is present on some parts of the 

 body of some species as has already been noted under the 

 description of the various integumental appendages. 



The various species may be classified according to the 

 coloration of their pile under the following heads : 



1. Unicolorous. Entirely black species of which there are but few 



{kohli, niger, etc.)- 



2. Bicolorous. These are as follows : 



(a) black and yellow (e. g. — impatiens, morrisoni, sonoriis) . 



(b) black and ferruginous (e. g. — dahlbomii, dolichocephalus) . 



(c) black and white (e. g.^'unebris). 



TRANS. AM. ENT. SOC, XXXVIII. 



