No. 22.] HYMENOPTERA OF CONNECTICUT. 739 



H. ziziae (Robertson). 



Hartford (S. N. D.) ; Milldale, 21 May, 1906 (B. H. W.). 



H. modestus (Say). Pro so pis afhnis Smith. P. illinoiensis 

 Robertson. 



On the wing throughout the state in June, July, and August, 

 on flowers of common meadow-sweet, parsnip, milkweed, golden- 

 rod, and common day-lily. Has been taken at Branford, Cole- 

 brook, Green's Farms, Mt. Carmel, New Haven, Sachem's Head, 

 Salisbury, Scotland, Stafford, and Westbrook. 



H. sayi (Robertson). 



H. varifrons (Cresson). 



H. verticalis (Cresson). 



H. pennsylvanicus (Cockerell). 



H. nelumbonis (Robertson). 



colletim:. 



These bees burrow in the ground to make their nests. At least 

 one of the indigenous species groups its nests into communities 

 which the late Dr. Henry Christopher McCook has called "bee 

 towns." A single genus occurs in the state. 



Colletes Latreille. 

 Key to Species. 



Females. 

 i. Fore coxae without distinct hairy spines; dorsum of thorax 



with griseous pubescence, mixed with black 2 



Fore coxae with distinct hairy spines 4 



2. Sixth ventral abdominal segment simple; propodeum truncate 



and with a transverse series of subquadrate pits; postscutel 

 anteriorly without a transverse series of subquadrate pits; 

 clypeus in profile slightly convex, somewhat sulcate, 



puncto-striate 3 



Sixth ventral abdominal segment bicarinate; propodeum 

 rounded and with a triangular, reticulated, rugose en- 

 closure; third antennal joint longer than fourth or fifth; 

 malar space one-third as long as wide; length 9-11 mm. 



compactus 



3. Malar space more than one-third as long as wide, but shorter 



than wide; clypeus shining, coarsely puncto-striate; trans- 

 facial line longer than facial; length 12-13 mm inaequalis 



