No. 22.] HYMENOPTERA OF CONNECTICUT. 755 



that, when in the act of building, these bees form a line from the 

 site of the prospective nest to the moss supply, all facing the moss ; 

 the first bee bites off a piece of the moss, cards and rolls it with its 

 jaws and feet, then passes it on to the second bee, where it is again 

 manipulated and passed to the third ; and so it goes along the line 

 until it reaches the nest, where it is incorporated with wax into a 

 dome-like structure. No such habits have as yet been observed 

 in connection with our native species. 



Key to Species. 



Females and Workers, 



1. Vertex with black pubescence like mesonotum 2 



Vertex with yellow pubescence like mesonotum 7 



2. Mesonotum with a band of yellow pubescence in front; base 



of labrum as in vagans 3 



Mesonotum with yellow pubescence, and some black hairs in 

 center; base of labrum with two elevations; other pubes- 

 cence similarly colored to pubescence in var. consimilis vagans 



3. Scutellar hairs pale 4 



Scutellar hairs black, sometimes mixed with yellow; second 



and third dorsal abdominal segments with yellow pubes- 

 cence 6 



4. Scutellar hairs yellow 5 



Scutellar hairs yellow with the exception of an admixture of 



black hairs; first and fourth dorsal abdominal segments 

 with yellow pubescence, second and third with orange, 

 fifth and sixth with black, and venter with black pubes- 

 cense; malar space as long as wide temarius 



5. First to fourth dorsal abdominal segments with yellow pubes- 



cence; malar space slightly longer than wide fervidus 



First dorsal abdominal segment with yellow pubescence, 

 second with pubescence yellow and brownish; malar space 

 wider than long affinis 



6. Apical dorsal abdominal segment with blackish pubescence, 



first segment with yellow pubescence, mixed with black on 

 lateral basal angles, or entire basal portion black, apical 

 margin always with yellow hairs more abundant in middle 



pennsylvanicus 

 Apical dorsal abdominal segment with yellow hairs, basal 

 segment with black pubescence terricola 



7. First dorsal abdominal segment not the only dorsal segment 



with yellow pubescence; malar space as long as or longer 



than wide 8 



First dorsal abdominal segment only with yellow pubescence; 

 disc of mesonotum with black hairs; labrum with a basal 



