66 COSTA RICAN DIPTERA 



Subfamily Ephydrinae 



Of this subfamily there seems to be few species represented 

 in Costa Rica, or even in South America. The species, in con- 

 tradistinction with those of Notiphilinae, have the frontal 

 bristles curving laterally over the eyes; the median, lower por- 

 tion of the face is more or less projecting and satulose, with the 

 facial bristles, if differentiated, arranged in series which con- 

 verge and are sometimes contiguous above, not paralleling the 

 orbits. The oral opening is large and cavernous. 



The genera are characterized sufficiently in the tables and 

 will not be further treated here unless deserving special com- 

 ment. 



EPHYDRA 

 Ephydra rostrata new name PI. Ill, fig. 27. 



1896. Ephydra pygmaea Williston, Tr. Ent. Soc. London, 1896, 402, (xiii, 

 147-a), nee Ephydra (Atissa) pygmaea Hal., 1833. 



This species is not typical of the genus. It may be distin- 

 guished by the unusual prolongation of the lower, convex, 

 sparingly bristled part of the face, which in profile is nearly as 

 long beyond the orbits as the diameter of the eye. It is black, 

 with halteres yellow. All upper surfaces, including the face, are 

 shining, metallic tinged, sparingly dusted with brown. Frontal 

 stripes velvety black. 



Only one specimen of this species was collected, along a ditch 

 in Cartago, February 10. 



SCATELLA 

 ScateUa stagnalis FaUen PI. Ill, fig. 22. 

 1813. Ephydra stagnalis Fallen, Act. Holm., 248. 

 1849. Scatella stagnalis Walker, List, iv, 1104. 



This species has the face evenly greenish brown; cheeks, pleura 

 and under surfaces not noticeably gray ; wings more or less black- 

 ened, with clear or white spots as shown in figure. There is a 

 pair of strong acrostical bristles near the suture, but no strong 

 anterior dorso-centrals. 



The specimens examined and determined as this species are 

 smaller than those of the nearctic region, and are more shining 



