LIMNOPHILA. 199 



is that of Dactylolabis, with the following differences : the cliscal 

 cell is open and coalescent with the fourth posterior cell ; there 

 is a supernumerary cross-vein in the first submarginal cell. The 

 body is shorter and stouter, the feet stronger than in Dactylolabis. 

 These differences notwithstanding, I do not think that the sepa- 

 ration of Rhicnoptila from Dactylolabis is necessary. The only 

 species, P. icodzickii, occurs in Austria. 



3. The subgenus Lasiomastix 0. S. (Proc. Acad. Nat. Sci. 

 Philad. 1859, p. 233). Very long filiform antennas in the male, 

 about as long as the body, with a long, erect pubescence on the 

 flagcllum ; palpi unusually long ; forceps somewhat peculiar, etc. 

 (compare below, the description of the species). Only a single 

 North American species, L. macrocera Say, is known. The 

 Limnophila longicomis Locw, contained in amber, seems to be 

 related to this species. 



4. Subgenus Dicranophragma 0. S. {Proc. Acad. Nat. Sci. 

 Philad. 1859, p. 240), distinguished by a cross-vein, connecting 

 both branches of the second vein. The only North American 

 species, D. fuscovaria, is a delicate, rather small species, with 

 slender feet and broad wings, rounded posteriorly, and densely 

 spotted with brown. 



5. Idioptera, introduced as a genus by Macquart'(I?2,'s£. Natur. 

 Dipt. I, p. 94), has been adopted in Dr. Schiner's work (1. c. II, 

 p. 548). It is principally based upon the presence of a super- 

 numerary cross-vein in the second basal cell. The antennas of the 

 male are much longer than those of the female, filiform, pubes- 

 cent ; the body slender, the wings banded with brown, etc. Two 

 European and one North American species are known ; they are 

 very closely allied, and the picture of their wings is nearly the 

 same. The wings in the female of one of the European species 

 are abortive. 



6. Ephelia, a genus introduced by Dr. Schiner (1. c. II, p. 549), 

 is likewise based upon the presence of a supernumerary cross- 

 vein in the second basal cell ; the antennas are short in both 

 sexes, the wings are rather broad and spotted with brown, the 

 spots lying along the margin and on the veins. Two European 

 and one American species are known. The forceps of the latter 

 (Tab. IY, fig. 23) has the outer horny appendages stout, blunt, 

 bifid at the tip, and therefore sufficiently distinct from the usual 



