80 THE CANADIAN ENTOMOLOGIST. 



Sauss. The Odynerus cells were built of clay, upon the under surface of 

 a stone, and formed a compact mass which could not be removed without 

 rupturing the cells, as their silken lining adhered directly to the uneven 

 surface of the stone. 



Chrysis parvula, Fabr. 



This pretty species very closely resembles the preceding, but is 

 easily separated by the shape of the terminal segment of abdomen, which 

 is truncate and tridentate (the central tooth strongest), instead of quadri- 

 dentate, with curved emarginations separating the teeth. Two examples 

 were bred from cocoons taken from the cells of Pelopceiis cemeniarius, 

 Drury, the slender-bodied wasp whose large clay-built groups of cells are 

 so frequently seen under window-sills and other ledges in the city, and 

 are placed under stones in the fields. The cocoon of the parasite 

 occupies one end of the cell made by the industrious wasp as a home for 

 its own young, and is almost identical in shape and colour with that of 

 the other Chrysid. The insects emerged on June 2nd and 4th, the cells 

 having been obtained some weeks previously. Mr. Ashmead has 

 recorded (Psyche, Vol. VII., p. 79) the rearing of C. perptdchra, Cr., 

 and C. coerulans, Fabr., from the same host. 



Ceropales fraterna, Smith. 



While searching, one day in early spring, for the potato-like galls 

 which are produced by Tribalia upon the roots of wild roses, I found 

 under a flat stone, slightly imbedded in the turf, about a dozen fusiform 

 hymenopterous cocoons, about 15 mm. long. They were scattered on 

 the surface of the soil, and some had already become mouldy from the 

 dampness of the ground. From those which were not so affected 1 

 obtained in due time a female and four males of Pompilus luctuostis, Cr., 

 which liberated themselves by neatly cutting off the large end of the 

 cocoon. From one of the larger cocoons there emerged in the same 

 manner, instead of the velvety-black Pompilus, a long-legged, yellow- 

 banded Ceropales. 



Agenia architecta, Say. 



The mud cells of this pretty little blue wasp are not uncommon 

 under stones in dry fields near woods. They are cylindrical in shape, 

 and several may be found on the same stone, but they are not massed 

 together and cemented into one lump, as are those of the mud-wasps 

 previously mentioned. The wasps have been bred several times, but I 

 have as yet reared no parasites. 



