114 Journal New York. Entomological Society. [Voi. v. 



traded. The segments above not very convex, though the sutures are 

 very distinct and well impressed. Laterally they dilate into a large 

 subacute tubercle. The end of the body is smooth, rounded, subacute. 

 There are no hairs. Color dusky, white on the head and end of the 

 body. Length of body, .20; width, .05 inch. 



Bombus fervidus. 



Nesting-habits, Larva and Pupa. — The nest and young of this spe- 

 cies, together with the bees, were found by Mr. F. W. Putnam, at Brid- 

 port, Vt., August 5, 1863. The nest occurred with several others un- 

 der the grass in deserted mice nests. There were only three imago bees 

 in the nest, as it was collected at noon time when the rest of the colony 

 was out. One bee, however, left its cell soon after the brood was col- 

 lected.* 



All the workers, sixty-five in number, had escaped from their cells 

 and deserted the nest, the brood-cells having had their upper third ir- 

 regularly eaten away. The bodies of four or five workers remained in 

 certain cells in which they had died. I have never found any traces of 

 ichneumon parasites in any Bovibus nest. 



Dimorphic Forms. — The colony also contained 13 males, 5 small 

 and 8 large individuals ; also 9 queens, of which 3 were small and 6 

 large. The measurements were as follows : 



Average length of 4 workers with the hair all grown, .55 in.; 

 breadth, .35 in. 



Average length of 3 females, with the hairs just beginning to grow, 

 .62 ; breadth, .38 in. 



Average length of 6 females, naked and white, .67; breadth, .43 in. 



Average length of 5 males, dark and hairy, .52 ; breadth, .30 in. 



Average length of 8 males, naked and white, .55 ; breadth, .33 in. 



From this it will be seen that there are two sizes of males and two 

 of females, among bumble bees. Whether this holds good for the 

 workers i uist be proved by further observations. 



In the two sets of males and females there was as much variation in 

 length between the individuals as between the two sizes taken collect- 

 ively. The difference in size between the smallest males and females 

 was .10 inch, and the difference in size between those of the larger set 

 was from .01 to .12 inch; the difference in size between the smallest 

 male and the largest female was .25, being .3 more than one-half the 

 length of the smallest male. 



* Also see notes on the habits of some species of bumble bees, by F. W. Put- 

 nam, Proc. Essex Institute, IV, October, 1864, 98-104. 



