DURHAM DIPTERA. 97 



XV. 150. 



2 (3). Abdomen with black marks; wings in both sexes 



dusky brown. (891. clavipes, L.) 



3 (2). Abdomen without black marks ; wings dusky brown 



in the male, yellow brown in the female, with large 

 dark brown stigma. 



892. Berts Valletta, Forst. 

 Bishop Auckland, 1 ?, 19-7-00. 



4 (1). Abdomen violet, or shining metallic brown, or dull 



black. 



5 (10). Wings dusky brown ; legs chiefly blackish or brownish. 



6 (9). Dorsum and scutellum shining black. 



7 (8). Legs almost entirely yellowish brown; hind meta- 



tarsus very thick, and scarcely longer than the 

 four other joints together. 



893. Berts chalybeata, Forst. 

 Common, Bishop Auckland, n $, 9 ?, May-June. 



8 (7). Legs dark brown with pale knees ; hind metatarsus 



moderately thick, and distinctly longer than the 

 other four joints together. (894. fuscipes, Mg., £) 



9 (6). Dorsum and scutellum shining metallic blue. 



895. Berts geniadata, Curt. 

 Bishop Auckland, 1 $, 2 $, 1 1-7-00, 1 $, 26-6-01; 

 Hesleden, 2 $, 1 $, August, 1902. 



10 (5). Wings yellowish brown, legs mostly yellow. 



11 (12). Eyes either touching, or separated by not more than 



the fifth of the width of the head. 



(896. morrisii, Dale.) 



12 (11). Eyes separated by fully one-third of the width of the 



head. 



13 (14). Hind metatarsi much longer than the remaining four 



joints together. (884. fuscipes, Mg., 5 ) 



14 (13). Hind metatarsi scarcely longer than the remaining 



four joints together. chalybeata, Forst., $ (893) 



