24 DIPTERA OF NORTH AMERICA. [PART II. 



25. separatus Walk. Bad description of a female, rendering identifica- 

 tion impossible. 



20. terminatus Walk. Also a female described. The only species to 

 which it may possibly be referred is D. chrysostomus, and I would 

 have no doubt about it if I knew that the cilia of the tegulse of D. 

 terminatus are black. But Mr. Walker's description is silent about 

 this ; neither does it mention the very striking black incisures 

 which the abdomen of D. chrysostomus shows; finally, the third 

 joint of the antennae of the latter species is pointed at the tip. Con- 

 sidering all this, it would be premature to assume the identity of 

 these species. Those who. in the determination of the species, rely 

 upon possibilities and vague reasonings, would perhaps do so. And 

 doubtless it is that the adoption of this synonymy would be more 

 reliable than that of any other of Walker's species with one of those 

 described by me. 



27. sequax Walk. Mr. Walker says that this species has small tufts of 



black hairs at the basis of the middle tibiae. He does not mention, 

 however, whether this peculiarity is to be found in the male alone, 

 or in both sexes - . At all events this is a very unusual distinction 

 among the species of Dolichojiidw, which will render the identifica- 

 tion easy. This species is not among those described by me. 



28. soccatus Walk. The sex of the described specimen is not men- 



tioned ; it seems to have b»en a female. The description is too in- 

 complete to allow recognition. 



29. remotus Walk. Description of a male with plain tarsi. The cha- 



racters given allow a comparison merely with D. incisuralis, the 

 male of which, however, has fringed hind femora and cannot there- 

 fore be identical with D. remotus. 



30. D. irrasus Walk. This is a small species, distinguished by its dark 



blue color and unusually short abdomen, which is certainly not to 

 be found among the species known to me. It seems probable that 

 it is no true Dohchopus at all. 



The slender result of the foregoing discussion of Mr. Walker's 

 species is, that there are only two among them which, with cer- 

 tain problematical admissions, may perhaps be identified with 

 species described by me, namely, D. conterminus Walk, with my 

 D. splendidus, and D. terminatus with D. chrysostomus. 



To facilitate the determination of the species I give, first, a 

 dichotomic table. I found it impossible to bring it down to the 

 single species without making use of characters peculiar to the 



