DURHAM DIPTERA. 107 



XIX. 



2 (1). Eyes almost touching in the male. Proboscis long. 



3 (4). 0.6. closed. 



182. Phthiria, Mg. (973. pulicaria, Mik.) 



4 (3). 0.6. open. 0.4 2 closed. Bombylius, L. (181) 



180. Anthrax, Scop. 

 Larvas parasitic in caterpillars. 



1 (2). Wings basal, two-thirds brown, with four clear spots. 



(967. fenestrates, Fin.) 



2 (1). Wings unmarked. 



3 (4). Abdomen all black in male, or with two light bands 



in the female. (965. fianiscus, Rossi.) 



4 (3). Abdomen black with white rings on the hind margin 



of all segments. (966. hottentota, L.) 



181. Bombylius, L. 



Life history not certainly known, probably parasitic on 

 other insects. 



1 (4). Wings with the front half dark brown, sharply 



bounded. 



2 (3). Hinder half of the wings spotted. 



(968. discolor, Mik.) 



3 (2). Hinder half of the wings clear. 



969. Bombylius major, L. 

 Common on warm sunny days about the end of 

 April at Gibside and Hesleden hovering over 

 labiate flowers and primroses. It disappears 

 instantly at the slightest movement, but if perfect 

 stillness be observed it will often return to the 

 same spot. 



4 (1). Wings mostly all clear, or with only the base and 



front margin somewhat clouded, but not sharply 

 bounded. 



5 (6). Back of the head long-haired. Posterior orbit with 



a row of black hairs. (971. canescens, Mik.) 



6 (5). Back of the head with short cropped hairs. Posterior 



orbit without black hairs. 



