96 DURHAM DIPTERA. 



XV. 147. 



147. Sargus, F. 



Larvae in cow-dung, garden earth, and under stones. 



1 (2). Legs all yellow, or at least the hind tibiae all yellow. 



883. Sargus flavipes, Mg. 

 Hesleden, 3 $, 1 ?, August, 1899 and 1900. 



2 (1). Legs all black, or brown with yellow knees. 



3 (4). Legs brown with yellow knees. 



885. Sargus cuprarius, L. 

 Bishop Auckland, 1 ?, 9-6-97 ; Hesleden, 2 $, 

 August, 1902. 



4 (8). Legs black. 



886. Sargus tridatus, Scop. 

 This is our commonest species. A handsome fly 

 with rather smoky wings, blue metallic thorax, 

 and violet abdomen. 



149. MlCROCHRYSA, Lw. 



Larvae have been found under stones. 



1 (2). Legs for the most part black. Antennae black. 



888. Microchrysa polita, L. 

 Bishop Auckland, 2 $, 6 % June- July, 99-01 ; 

 Hesleden, 1 $, 15-8-00. 



2 (1). Legs and antennae for the most part yellow. 



3 (4). Antennae brownish or tawny. Abdomen brassy, 



thorax with white side stripes ; larger species, at 

 least 2 mm. 



889. Microchrysa flavicomis, Mg. 

 Bishop Auckland, 4 $, 25-6-01, 1 $, 20-7-01. 



4 (3). Antennae yellow, abdomen violet; small species, 



1 J mm. (890. cyaneiventris, Ztt.) 



150. Beris, Ltr. 

 Life history unknown. 'Pupa of 893 has been found in moss. 

 1 (4). Abdomen orange. 



