152 NORTH AMERICAN DIPTERA. 



2. Ungues slender and rather long tenuipes. 



Ungnes stout and shorter. jordani. 



BIBIOCEPHALA. 



1. Eyes contiguous; anterior branch of second vein running into vein 



near margin of wing ; eyes bisected ; front femora of male 



strongly curved. , grandis. 



Eyes separated by a narrow or broad space, in both males and fe- 

 males; fore femora of male straight 2 



2. Eyes in both sexes bisected. ....... 3 



Eyes of male bisected, of female not bisected; anterior branch of 



second vein running into the first very soon, making a triangle 

 in which the anterior branch forms the shorter side. doanei. 



3. Eyes of male separated widely; of female narrowly; anterior branch 



of second vein running into first vein very soon, forming a 

 nearly equilateral triangle. .... elegantula. 

 Eyes of both male ami female separated narrowly; anterior branch 

 of second vein running into first aboiit one-third the distance 

 from origin of second to tip of first vein. . comstocki. 



PHILORUS. 



Philorus is represented by but two known species in America, viz: 

 yosemite and ancilla, and by one species in Europe, bilobata L,oew; of 

 the two American forms, P. ancilla has the eyes contiguous (in the 

 female at least) , while the eyes of P. yosemite are separated by a broad 

 front (in the male at least) . 



PALTOSTOMA. 



Paltostoma is known by a single described species from the West 

 Indies, and another from Brazil; one or the other or possibly a third 

 is known also from Central America. P. schineri will be recognized 

 from the generic characters and the figure. 



