126 THE CANADIAN ENTOMOLOGIST 



7 Ottawa males average length 9.50 mm. 

 7 Ottawa females average 10.75 mm. 

 5 Dover males average length 10.70 mm. 

 5 Dover females average length 12.80 mm. 

 4 Pacific Coast females average length 14 mm. 

 In England, Anthophora fnrcaia is very faithful to its food plant, Stachys 

 sylvatica, and the Canadian forms may always be found on Stachys palustris. 

 Saunders notes that it burrows in "'dead wood," although other species of the 

 genus burrow^s in the ground. Attracted by a heap of white sawdust around 

 a decayed but still hard stump near Hull, P. Q., on August 16th, 1913, I found this 

 to be riddled with the burrows of Clisodon terminalis. The exceedingly active 

 females, resembling honey-bees in appearance and size, passed in and out of 

 numerous holes in the stump as frequently as the workers of a strong colony of 

 bumble-bees. 



Bombus and Psithyrus. 

 These northern genera, so rich in biological material, furnish an interesting 

 contribution to this study. They never develop felt bands but there is a uni- 

 form coat of long hair resembling fur. 



Bombus borealis Kirby.* 

 Bombus borealis Kirby, fairly common and widely distributed in the boreal 

 region of Canada east of the Rocky Mountains has its British representative 

 in B. distinguendus Morawitz, the distribution of which, according to Hoffer, 

 extends to Siberia. Here again the pattern and even the tint of the coat, deep 

 greenish yellow with a black band across the thorax, very variable in most 

 species of Bombus, is common to both forms with the unimportant exception 

 of more or less black hair on the last segment of borealis, but the British specimens 

 are larger (average length of females 20 mm. compared to 18 mm. in borealis) 

 and they have a much longer and more uneven coat. 



In the Mountains and Pacific Coast region, borealis is replaced by a form, 

 appositus, that is intermediate in size between British distinguendus and borealis, 

 having a coat slightly longer than borealis and the yellow band on the anterior 

 part of the thorax very pale while there are no black hairs on the abdomen. 

 Appositus is evidently still more closely related to distinguendus than is borealis. 

 In both the Old and New Worlds, the queens of all these forms appear later in 

 the spring than those of almost every other species of Bombus. The colonies 

 consist of comparatively few workers, and the young queens and drones are 

 raised early. The period of activity therefore lasts a shorter time than in the 

 case of the other species. 



Bombus terrestris L. 

 One of the commonest and most aggressive species of Bombus in England 

 and the continent of Europe is terrestris L. This is represented in Canada from 

 the Atlantic Coast to the Mountains by an equally common and aggressive 

 species, B. terricola. In habits, terricola agrees with terrestris not only in those 

 common to the terrestris group such as biting holes at the bases of flowers, but 

 also in the unique habit that separates terrestris from its close ally in England, 

 lucorum, of continuing to leave its winter quarters in small numbers from the 

 opening /of spring right on until about mid-July when all other species have 

 *This name has priority over distinguendus. 



