No. 22. J HYMENOPTERA OF CONNECTICUT. 677 



T. clavatum Say. 



Length about 14 mm. Pubescence white; hind tarsi partly 

 pale; males with a spine on the hind trochanter. According to 

 Ashmead this species uses the cells of Chalybion cceruleum for a 

 nest, and it has been observed to nest in deserted holes in boards. 



Has been taken in the State in July and August. Will perhaps 

 be found only along the coast and in the river valleys. New 

 Haven, 14 July, 1904 (W. E. B.). 



T. tridentatum Packard. 



Length about 8 mm. Pubescence white; males without a 

 spine on the posterior trochanter ; front with rather large, close 

 punctures ; ocelli separated from the inner margin of the eye by 

 about their width. 



This species has also been recorded from the State. Its 

 general distribution is more southern, however, and it may 

 also be restricted to the coast and river valleys. 



T. frigidum Smith. 



Length about 8 mm. Entirely black. 



This is a northern species and has been taken at Branford, 

 June 1905 (H. L. v.). 

 °T. bidentatum Fox. 



Closely allied to frigidum and has a similar distribution, so 

 will no doubt be found in the State. 



Mellinin^. 



Mellinus Fabricius. 

 The habits of the American species of this genus have not as 

 yet been worked out, but the European species, M. arvensis, nests 

 in sand and provisions its nest with small Diptera, including 

 Stomoxys calcitrans (the stable fly). 



°M. bimaculatus Harris. 



Not as yet taken in the State but no doubt occurs there. 

 Length about 9 mm. Clypeus with a low produced portion which 

 is sub-tridentate ; third antennal joint very little longer than the 

 fourth ; head and thorax finely granular, opaque ; abdomen shin- 

 ing; dorsal aspect of the propodeum with a U-shaped area. 

 Black ; inner margins of eyes, line on pronotum, two spots on the 

 third dorsal segment, and legs in part yellow. Wings hyaline. 



