108 DURHAM DIPTERA. 



XIX. 181. 



7 (8). Legs dark. Femora almost entirely black. 



(970. fugax, W.) 



8 (7). Legs light. Femora yellow, at most only black at 



the base. (97 2. minor, L.) 



Family XX.— THEREVID^E. 



TABLE OP GENERA. 



1 (4). Face thickly haired. 



2 (8). 0.4.b.b. closed. Thereva, Ltr. (183) 



3 (2). 0.4. b.b. open. 



184. DiALiNEURA, Rnd. (980. am'/is, L.) 



4 (1). Face bare. 185. Psilocephala, Ztt. (981. ardea, F.) 



183. Thereva, Ltr. 



The wormlike larvae live in slime and rotting tree trunks. 



The specific characters given by Schiner are not very clear, 

 but there seem to be three or four species among the long 

 bent grass at Hart. One with VAb.b. open, which, according 

 to Schiner, would be a Dialineura, is otherwise so exactly 

 like another with the same cell closed that I doubt the 

 worth of the character. There may be another which I 

 cannot name, and two more which I take to be : 



1 (2). A brownish species. 



974. Thereva nobilitata, F. 

 2 $ and 4 $, Hart sands, August, 1902. 



2 (1). A pale grey white-haired species. 



979. Thereva annulata, F. 

 6 «£ and 3 $, Hart sands, August, 1902. 



Family XXL— SCENOPINID2E. 

 186. Scenopinus, Ltr. 

 Larvae in tree fungi. 



1 (2). Legs black, only the tarsi yellowish. 



(983. niger, Deg.) 



2 (1). Legs yellowish. 



