ZooL.— Vol. III.] KELLOGG— NET-WINGED MIDGES. 197 



Janeiro, Brazil), and Paltostoma (Columbia, South America, 

 Mexico and West Indies). 



The remaining known species are grouped, in the latest 

 revision (Osten-Sacken, 1895) of the family, into four 

 genera, of which two, Bibiocephala and Agathon, each with 

 a single species, are recorded only from the western United 

 States, while the other two, Blepharocera and Lipoiieura, 

 with respectively three and four species each, have repre- 

 sentatives in both Europe and the United States. The 

 species recorded from North America, according to this 

 revision, are Blefharocera capitata (Northeastern United 

 States and reaching far north), Blepharoce7-a ancilla\Q^\- 

 fornia), Liponeura yosemite (California), Bibiocephala 

 grandis (Rocky Mountains, Colorado), and Agathon 

 elegantulus (Nevada). Of these species male specimens 

 alone are known of Bibiocephala, Agathon and Liponeura ; 

 females alone of Blepharocera ancilla, and both sexes of 

 Blepharocera capitata. In the light thrown upon the value 

 of the characters used by Loew, Osten-Sacken, and von 

 Roder in their establishment of genera, by the four new 

 species described in this paper, of which males and females 

 are known in every species, it becomes necessary to suggest 

 a re-revision of the Blepharocerid genera. This suggestion 

 is made with distinct reluctance, but the simple observation 

 of the existing facts dictates it. 



The contiguity or separation of the eyes, and their 

 bisection, have been relied on as generic characters; but it 

 is obvious from the conditions shown by the new species 

 Bibiocephala doanei, in which the eyes of the male are 

 bisected while those of the female are not, and from the 

 condition of Bibiocephala (Agathon) elegantidns, where the 

 males have the eyes separated by a broad space while the 

 eyes of the female are subcontiguous, that such distinctions 

 cannot distinguish genera, if, indeed, even specific value 

 may be given them. On the other hand, an inspection of 

 the venation of the wings shows that forms with identical 

 venation or with variations amounting (as will be shown) 

 simply to slight differences in degree, not in kind, have 



