SCIENTIFIC SURVEY. I53 



iptera, Lepidoptera, Hymenoptera, Diptera and spiders, contributing 

 to the support of this tribe ; and insects in the larva, pupa and 

 imago state are employed for this purpose. The number of indi- 

 viduals enclosed in each cell varies according to tire size of the 

 species, and of the progeny for whose support it is buried : thus, 

 whilst Ammophila sabulosa buries a single lepidopterous larva, as 

 many as fifty or sixty Aphides are shut up in a single cell by other 

 species." Weslwood. 



Crabronidae, sand-wasps. It is this family that many of the 

 Syrphus-flies resemble so closely. They have cuboidal heads, 

 a somewhat flattened, spherical thoi'ax, and a flattened abdomen, 

 rarely pedicelled. The fore legs are broad, adapted for digging, 

 and they often have a broad, banner-like expansion, to use perhaps 

 as a shovel, while the hind and middle legs are spiued for retaining 

 the prey the sand-wasp carries off. The insects are of moderate 

 size ; they are found resting on leaves in the sunshine. They occur 

 generally rarely, and little is known of the extent or habits of the 

 family in this country. Crabro (Fig. 5) has slender legs, and digs 

 into rotten posts, fences, stumps, where it Fig. 5. 



makes its nest, provisioning it with cater- 

 pillars, flies, &c. Gorijtes has been seen 

 protruding her sting into the frothy secre- 

 tion of Tettigoniae on grass, and carrying 

 off the insect. Oxyhelus is a small,' stout 

 black genus, "its prey consists of Diptera, 

 which it has a peculiar mode of carrying by the hind legs the while it 

 either opens the aperture of its burrow or else forms a new one with 

 its anterior pair. Its flight is low, and in skips ; it is very active." 

 Tnjpoxylon has a long, club-shaped abdomen, and is black through- 

 out. " Mr. Johnsbn has detected it frequenting the holes of a post 

 pre-occupied by a species of Odynerus, and into which it conveyed 

 a small round ball, or pellet, containing about fifty individuals of a 

 species of Aphis ; this the Odynerus, upon her return, invariably 

 turned out, flying out with it, held by her legs, to the distance of 

 about a foot from the aperture of her cell, where she hovered a 

 moment, and then let it fall ; and this was constantly the case till 

 the Trypoxylon had sufficient time to mortar up the orifice of the 

 hole, and the Odynerus was then entirely excluded ; for although 

 she would return to the spot repeatedly, she never endeavored to 

 force the entrance, but flew off to seek another hole elsewhere. 



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