108 NORTH AMERICAN DIPTEBA. 



3. Anal cell present. . 5 



Anal cell wanting. . . SIOALOKSSA Loew. 



4. Eyes prominent; wings straight PIIORTICA Schiner. 



Eyes not prominent; wings usually appearing as though broken and 



bent downward ; larger sized species. . . STEGANA Meigen. 



5. Gosta distinctly bristly ; auxiliary vein distinct in its proximal part. 



QJJRTONOTUM Macquart. 

 Costa not bristly. . ... . . DHOSOPHILA Fallen. 



38. EPHYDBIM:. 



Face more or less, often remarkably convex. Antennae 

 short ; first joint small ; antennal arista bare or pubescent or 

 pectinated on the upper side. Oral cavity rounded, usually 

 large ; clypeus distinct, in some cases retracted into the oral 

 cavity, in others prominent. Abdomen of variable form, com- 

 posed of six segments in the males, seven in the females, 

 sexual organs usually retracted. Auxiliary vein coalescent 

 for the most part with the first longitudinal vein, distinct 

 only at its proximal end ; second basal cell confluent with the 

 discal cell, the small vein separating them entirely absent, or 

 scarcely visible (present in Canace Hal. only); anal cell im- 

 perfect and small (distinct in Canace); alulae small. 



The flies of this family are never large, often small or even 

 minute. The greater number of the species are inhabitants 

 of wet places, about marshy ground, meadows, etc. They are 

 always thinly pilose or bare species, and never with bright 

 colors. The exceedingly large head and mouth of some spe- 

 cies are very characteristic, but in others this character is not 

 so apparent and there is sometimes difficulty in separating the 

 genera from those of the Drosophilidse. The larvae of many 

 forms are very peculiar, resembling the rat-tailed larvae of the 

 Syrphidae in many cases. The mouth, however, always has 

 booklets and the " tail " is forked at the end. The larvae of 

 species of Notiphila have been found in the stems of water 

 plants ; those of Hydrellia in the sap of trees, in the paren- 



