37§ DURHAM DIPTERA. 



LVI. 



3 (1) (2). V.4. and V.5. both broken off, or very faint beyond 



X.5 2 , and not reaching the margin (V. 39, VII. 28) ; 



X.5 1 and X.6. very indistinct or absent; scutellar 



bristles present. Limosina, Mcq. (658) 



TABLES OF SPECIES. 



656. Borborus, Mg. 

 Larvae live in dung. 



1 (2). Wings rudimentary. (2786. pedestris, Mg.) 



2 (1). Wings longer than the abdomen. 



3 (20). Black or dark brown species. 



4 (5). Hind tibiae without a thorn-like process beneath at 



the end. 



2792. Borborus geniculates, Mcq. 

 Bishop Auckland, 2 $ and 1 ?; Hesleden, 1 ?, 

 March-June, 1 898-1 901. 



5 (4). Hind tibiae with a thorn-like process at the end 



beneath (VI. 24). 



6 (13). Mid tibiae with bristles on the outer side. 



7 (10). Small black shining species, 1-2 mm. 



8 (9). Face and frons black ; X-veins clouded ; size about 



2 mm. (2783. suillorum, Hal.) 



9 (8). Face and frons orange ; wings clear ; size 1-1^ mm. 



(2785. pallifrons, Fin.) 



10 (7). Large species, 3-5 mm. 



11 (12). Fore femora with a row of bristles on the upper side; 



mid metatarsus as long as the next three joints 



together; male hind femora with a hooked thorn 



below at the base ; shining black. 



(2780. nitidus, Mg.) 



12 (11). Fore femora not bristly but thickly haired ; mid 



metatarsus as long as the next two joints ; male 

 hind femora not thorned ; brown-black, not very 

 shining. (2782. niger, Mg.) 



13 (6). Mid tibiae bare or nearly bare on the outer side. 



14 (17). V.4 4 not more than two and a half times the length 



of V.4 3 . 



