156 DOLICHOPIDJE. 



The British species being pretty numerous, the following 

 scheme may assist in the investigation of them : 



A. Hind metatarsus spiny. 



B. Cilia of the lower orbit black. 



a. Metatarsus with numerous spines (more than ten, in the male 



at least). Species 1, 2. 



a a. Metatarsus with few spines (less than ten). 

 b. Fore coxae blackish. 



c. Lamellae of male dusky. Species 3. 

 e c. Lamellae pale. 



d. Middle tarsi enlarged at the tip, in male. Species 4. 

 d d. Fore tarsi enlarged at the tip, in male. Species 5, 6. 

 d dd. Anterior tarsi simple in both sexes. Species 7, 8. 

 b b. Fore coxae pale in part. 



e. Posterior femora with several spines. Species 9. 

 e e. Posterior femora with single spine. Species 10, 11. 

 B B. Cilia of the lower orbit pale. 

 /. Face not descending lower than the eyes. 



g. Flexure of subapical vein obtuse-angled, simple. 



h. First joint of antennae entirely black. Species 1214. 

 h h. First joint of antenna? pale, at least in part beneath. 

 t . Middle tarsi of male marked. 

 k. With a white spot. Species 15. 

 k k. Partially enlarged. 



/. Posterior femora with a single spine. Species 16,17. 

 1 1. Posterior femora with several spines. Species 18. 

 i i. Fore tarsi enlarged at the tip, in male. 



m. Posterior femora with several spines. Species 19. 

 m m. Posterior femora with a single spine. Species 



20, 21. 



i i i. Anterior tarsi not enlarged in either sex. 

 . Hind femora not fringed in either sex. 



o. Costal vein swelled about the junction with the 



subcostal, in male. Species 22-24. 

 o o. Costal vein nearly simple in both sexes. Spe- 

 cies 25-28. 



n n. Hind femora fringed beneath, in male. 

 p. Femora dusky. Species 29, 30. 

 p p. Femora yellow. 



q. Costal vein without swelling. Species 31, 32. 

 q q. Costal vein with a swelling, in male. Species 



33, 34. 

 g g. Fracture of subapical vein forming alternate right angles, 



with a rudiment of a branch. Species 35, 36. 

 //. Face descending lower than the eyes. 



