246 DIPTERA OF NORTH AMERICA. [PART IV. 



is usually wrinkled and shrunken ; but in fresh specimens I have 

 counted (in E. longicornis Walk.) eight joints of the flagellum, 

 which would make the female antenna ten-jointed. 



The head is, as in Anisomera, closely applied to the collare, 

 which is narrow. The thoracic suture is well marked. The feet 

 are long and usually rather stout ; E. longicornis has a remark- 

 able character in the great shortness of the two anterior pairs of 

 femora, which are not much over half the length of the posterior 

 ones ; this character is much less striking in the other species ; it 

 is to be remarked, however, that the two anterior pairs of femora 

 seem to be rather inconstant in their length, in E. longicornis, as 

 well as in E. spinosa. In E. spinosa and E. longicornis the last 

 joint of the tarsi of the male is excised at its basis on the under 

 side, and also hollowed out and hairy in the middle of its under 

 side ; this character is not perceptible in E. wilsonii. Some of 

 the species (for instance E. spinosa) have a small projecting 

 tooth at the extreme basis of the ungues, on the under side ; but 

 it is difficult to perceive among the hairs which clothe the tarsi. 



The venation of the wings is exactly like that of some Limno- 

 philse. The auxiliary vein, the tip of which is more or less oppo- 

 site the inner end of the second submarginal cell, has the subcostal 

 cross-vein a short distance back from its tip. The marginal cross- 

 vein is a short distance anterior to the tip of the first longitudinal 

 vein ; its relative position to the inner end of the first subniar- 

 ginal cell depends on the length of the latter; sometimes the 

 cross-vein is inserted at this very inner end, sometimes beyond 

 this point. PraBfurca long, straight, arcuated at its basis only. 

 The inner end of the first submarginal cell, in all the species 

 which I have before me, is pointed, its petiole is either a little 

 shorter than the great cross-vein, or much longer ; the second 

 submarginal cell likewise varies in length, its inner end (which 

 is also pointed) projects more or less inside of the small cross- 

 vein towards the basis of the wing. It follows from this that the 

 first posterior cell is, in most cases, shorter than the second sub- 

 marginal ; in some cases they are subequal. The discal cell is 

 more or less square ; the section of the fifth longitudinal vein 

 lying beyond the great cross-vein is generally, but not always, at 

 an angle with the anterior portion of the vein ; the sixth and 

 seventh veins are straight. Three North American species have 



