ZooL.— Vol. II.] WHEELER— DOLICHOPODIDM. 



37 



the second joint of the antennae encroaches only very little 

 on the inner side of the third. In its general appearance 

 it approaches the species of Porphyrons very closely, so 

 that I leave it undecided whether it would not be better 

 located there. The size of the pulvilH of the fore tarsi 

 betrays a relationship with Etitarsus and Diaf horns, the 

 structure of the antennae, however, does not allow its loca- 

 tion in these two genera. To erect a new genus does not 

 seem advisable, as the species shows close relationship in 

 various directions." Loew's placing of this species in the 

 genus Synarthrus has led me into an oversight. I find that 

 I have redescribedthe species q.s Xtphandrhim americanum} 

 The species may therefore be known as Xiphandrtmn bar- 

 batum (Loew), if it really be a Xiphandrimn, which is 

 somewhat doubtful. For the present I will not decide on 

 its position, but will merely exclude it from the genus Syn- 

 arthrus. We then have left Loew's S. cinereiventris and 

 S. falmaris and the two new species described below, S. 

 affinis and S. stratcegus. Now these four forms all agree 

 in possessing females with peculiar broad faces which pro- 

 ject forward below like a roof. The males, however, re- 

 semble the males of Syntormon in that they have peculiarly 

 ornamented hind metatarsi. The remarkable facial structure 

 of the female is a character of sufficient importance to 

 justify separating these species from Syntormon as a dis- 

 tinct genus. In doing this I would reinstate Loew's generic 

 name Synarthrus for these species, since he first described 

 two of the North American species under this name, and 

 since the introduction of a new generic name would be 

 superfluous. There is in the Western States another group 

 of Dolichopodidse resembhng Syntormon and Synarthrus 

 in having an overlapping second antennal joint. These 

 also form a natural and compact group, rich in plastic 

 characters. For their accommodation I have erected the 

 genus Parasyntormon (q. v.). The males of the four 

 species of Synarthrus known to me may be tabulated as 

 follows: — 



i^nt. News., May, 1896, p. 154. 



