690 STATE BOAKD OF AGRICULTURE. 



compressed, wings broad and long, legs long. The larvse are slender, cylin- 

 drical, and live in decaying wood, under bark of trees, &c. 



HETERONEURA Fallen. 



H. latifrons Loew. Dunnfield, Del. Water Gap, VII, 8 to 15 (Jn), James- 

 burg, VII, 15 (Sm). 



H. albimana Meig. Delaware Water Gap, VII, 12. 



H. pictipes Zett. Westville, VI, 6, Riverton, V, 14. 



CLUSIA Haliday. 

 C. flava Meig.? Jamesburg, VII, 15 (Sm), Ft. Lee, IV (Love). 



ISCHNOMYIA Loew. 



I. vittata Loew. Westville, VII, 2, Dunnfield, Del. Water Gap, VII, 12, 

 Princeton, VII, 21. 



Family OPOMYZIDiE. 



Small flies with the chief characters of the Geomyzidce, but with a flattened 

 occiput and maculate wings. 



SCYPHELLA Desv. 

 S. flava Linn. New Brunswick (Sm). 



Family SEPSID.ffi. 



" The flies belonging to this family are usually small, black and elongated with 

 the abdomen narrowed at the base, thickened and curved downward toward the 

 extremity ; with transparent, iridescent wing, usually hyaline, but often with a 

 spot or spots toward the end, and are usually observed about decaying vege- 

 tables, excrement, cheese, ham, &c, often in swarms. The flies, for the greater 

 part, run about actively, and are quick in flight. The best known are the 

 species of Piophila s the larvse of which are known as ' cheese-mites. ' These 

 larvse live in cheese, in ham or bacon, or, in general, in any fatty material, 

 and often do much damage, being especially troublesome in pork-packing 

 establishments. From the peculiar power of leaping possessed by the maggots 

 they are often called ' skippers ' ; the act is performed by the larva seizing with 

 its extended mouth hooklets the edge of the posterior truncature of the body 

 and then suddenly releasing it while pulling hard." — Williston. 



