DURHAM DIPTERA. 1 85 



XXVIII. 279 



40 (41). Size 8 mm. The basal pair of spots on the second 



segment rather small, and the pair on the fifth 



segment hardly, if at all, visible. 



PL scutatus, Mg. (1484) 



41 (40). Size 6J mm. (1493. PL sticticus, Mg., but it is 



doubtful if the female has ever been taken). 



42 (37). Abdominal spots tending to triangles (VII. 12). 



43 (44). Face all shining, arista almost bare. 



M. mellinum, L. (1498) 



44 (43). Face partly dulled, arista slightly pubescent. 



M. scalare, F. (1499) 



280. Pyroph,ena, Schin. 

 Life history unknown. 



1 (2). Abdomen mostly orange, except at the base and tip. 



Male fore and mid metatarsus broad. 

 1494. Pyrophcena granditarsa, Forst. 

 Hesleden, 1 ?, 21-8-02. 



2 (1). Abdomen mostly black, except two yellow spots. 



Male tarsi simple. 



1195. Pyrophcena rosartwi, F. 

 Harperley, 1 ?, 28-6-02. 



281. Melanostoma, Schin. 



Life history doubtful. Larvae have been found attacking 

 the housefly, lepidopterous larvse, &c. See interesting account 

 of Syrphus larva? preying on lepidoptera, E.M.M., July, 1905, 

 page 150. 



1 (4). Abdominal marks faint or absent, not yellow. Male 



fore femora with a curled bristle near the tip. 



2 (3). Abdomen spotted. (1496. ambiguum, Fin.) 



3 (2). Abdomen almost without marks. (1497. dubium, Ztt.) 



4 (1). Abdominal marks distinctly yellow. Curled bristle 



absent in the male. 



5 (6). Face and frons brilliantly shining ; arista almost bare. 



1498. Melanostoma mellinum, L. 

 /Common everywhere. 



