SCIOMYZID^E. 127 



side of the last segment and then suddenly releasing them. 

 The puparia are yellowish, ellipsoidal and with two horns on 

 the last segment as in the larvae. 



TABLE OF GENERA. 



1. A long preapical bristle on the hind tibiae. HETERONEURA Fallen. 



No such preapical bristle on the hind tibiae. . CLUSIA Halliday. 



49. SCIOMYZIM;. 



Head rounded,* short, as broad or broader than the thorax ; 

 face more or less retreating ; mouth without vibrissse at its 

 border, sharp. Abdomen composed of six segments, rather 

 long and narrow. Wings longer than the abdomen ; auxiliary 

 vein present, distinctly separated from the first longitudinal 

 vein ; posterior basal cell and the anal cell complete. Legs 

 rather long ; preapical tibial bristle present. 



The members of this family are usually found in meadows, 

 along the banks of small streams, etc., wherever it is moist. 

 They are, for the most part, brown or brownish yellow in 

 color, oftentimes with pictured wings. They are slow in 

 their habits. The larvae are slender, cylindrical, thin anterior- 

 ly, the last segment with six or eight conical, fleshy tubercles. 

 They are aquatic. 



TABLE OF GENERA. 



1. Antennae short. . . .-_'..- .. :. ... 2 

 Antennae elongate. ... 4 



2. Face excavated, the oral margin protuberant. .... 3 

 Face retreating in profile, but little or not at all excavated; oral margin 



not at all prominent. .'.... . . SCIOMYZA Fallen. 



* The genus Trigonometopus Macquart, has been assigned to the Pyrgoti- 

 nce by Schiner, to the Heteroneurince by Loew. It will be sought for in this 

 family by the student, and I believe that it rightfully belongs here. It will 

 be recognized by its conically projecting head, and strongly receding face. 

 The cheeks have a row of well developed bristles situated on a ridge de- 

 scending from the front near the eye and extending back to the occiput; 

 the third antennal joint is rounded or a little elongated. 



