22 DIPTERA OF NORTH AMERICA. [PART II. 



the first joint ; besides, its male has ciliated hind femora, which 

 Mr. Walker does not ascribe to his species. D. luteipennis has a 

 white face and the last joint of its fore tarsi black ; its wings are 

 yellowish and not gray, the veins are luteous and not black ; finally 

 the hind femora of its male are also ciliated. If the tegnlse of D. 

 ciliatus are ciliated with black, then we might perhaps identify it 

 with D. vittatus ; but the size of the latter is too large to admit 

 of this identification, and its face, instead of being golden-yellow, is 

 whitish ; its fore tarsi are not dark tawny but always black from 

 the tip of the third joint. 



16. adjacens Walk. Very poorly described from a female specimen, so 



that it would be entirely useless to attempt its identification. 



17. coercens Walk. Mr. Walker says that the coxae are blackish-green 



towards the basis. This character, combined with the others which 

 are given, excludes at once all the species with the tegulae fringed 

 with black, which are known to me. If the tegulae are fringed with 

 yellow, this species might be taken for D. longimanus; but the last 

 joint of the fore tarsi of the latter is only moderately enlarged, 

 assuming the shape of a very small lamella, and its hind tarsi are 

 colored black in a rather striking manner from the very root of the 

 first joint ; whereas Mr. Walker says that in his species they are 

 pitch brown towards the end. Under such circumstances the des- 

 cription of D. coercens Walk, cannot possibly be referred to D. 

 longimanus. 



18. finitus Walk. If the tegulse are fringed with pale, then, among the 



species known to me, D. longimanus^ D. splendidus and D. batillifer 

 have to be taken in consideration. The face o/ D. longimanus is 

 not whitish, but pale ochre-yellowish in the %, and yellowish gray 

 in the 9 the cilia of the inferior orbit are not white, but yellowish, 

 and the hind tarsi are not pale at the basis, as in D. finitus, but en- 

 tirely black. D. splendidus is distinguished from D. finitus by its 

 hind tarsi, which are not pale at the base, and by the ciliated hind 

 femora of the male. The face of D. latillifer is not white : the hind 

 femora of the male are ciliated and the hind tibiae incrassated in a 

 very striking manner; therefore this species is also distinct from 

 D. finitus. If the cilia of the tegulae of D. finitus are black, then we 

 might compare D. chscifer and lobatus with it. The hind tarsi of 

 D. discifer are not pale at the base, and the first joint of the an- 

 tennae is tinged with black only on its upper edge, so that it is 

 hardly probable that Mr. Walker should have overlooked its 

 striking red coloring. This also excludes this species from the 

 identification with D. finitus. The hind tarsi of D. lobatus likewise 

 are not pale at the base, and the first joint of the antennae is red, 

 and only somewhat dusky on its upper edge, so that it has also to 

 be considered as different from D.finilus. 



