32G 
STUDIES IN AMERICAN EPHYDRIDAE (dIPTERA) 
The material upon which these studies are based is listed in 
the introduction to my first paperd Since then additional 
material has been received from the following sources: (’ali- 
fornia Academy of Sciences, [Cal. Ac. Sc.]; Museum of Com- 
parative Zoology, [M. C. Z.j; New York Academy of Sciences, 
Porto Rico Survey, through Dr. Frank E. Lutz, [N. Y. Ac. Sc.]; 
United States Department of Agriculture, Biological Survey, 
[Biol. Surv.]. To these also I extend thanks for the privilege 
of studying their collections. In cases where no source is given, 
it is understood that the material is from the collections at 
the Academy of Natural Sciences of Philadelphia. 
Subfamily Gymnopinae 
It is certainly advisable to consider the genera here included 
as reiiresenting a distinct subfamily, if they are to be admitted 
into the Ephydridae. They do not seem to intergrade with 
any other grou]), being at once recognizable by the sharp, iiost- 
buccal ridge. This ridge is the vertical keel or emargination 
separating the ])ost-buccal area from the occiput, and extends 
from the oral margin to near the post-orbits, vanishing there 
at about on the center line of the eyes. The known species 
have the following additional characters, which may be con- 
sidered of subfamily value. 
Head siibhemispherical; occiput entirely concaved. Eyes 
round or slightly oblicpie, bare; iiost-orbits visible in profile. 
Frons convex in jirofile, the areas weakly definetl; orbits jiarallel, 
with the usual vertical bristles; ocelli close, not tulxu-culate, 
with ])ost-ocelli removed from the vertex; orbital bristles iiro- 
clinate when ju’e-sent; no reclinate front als. Face (U'ejily ('x- 
cavat-ed lieneatli antennae for its (uitire width; lowin’ jiortion, 
in ju’ofile, ])i’omin(mt, convex or t ulx'rculate nu'dianly; ])ara- 
facialia dilating below into tlui bi’oad clu'eks; the groove distinct; 
facialia sonietinu's broad and sculiitured, beai’ing three or mori^ 
ajiiiressed medianly inclined bristles. C'heeks with well de- 
veloped ]K)st-buccal area, but no bristle. Clypeus strongly 
' Traus. Aiuor. Eiil. Six;., xiai, 101, 1010. 
