OP PHILADELPHIA. 367 



Orbits, except behind, silvery: front fuscous : [177] hyposto- 

 ma pale livid, with a dark lateral line bounding the orbits : an- 

 tennae yellowish, darker at base; seta blackish: thorax blackish : 

 tergum yellowish-white with a black line, which is somewhat 

 dilated at the tip of each segment; tip of each segment and tail 

 black : feet black ; coxae piceous. 



Length half an inch. 



Nervures of the wings arranged like those of D. rustica Fabr. 



2. D. ANALis. — Abdomen yellow, blackish at tip. 



Inhabits Indiana, 



Head silvery ; front tinged with dull yellowish : antennas yel- 

 lowish, tip of the third joint black : palpi yellow : proboscis 

 black, yellow at tip : thorax black, with a somewhat golden re- 

 flection ; a dull yellow line each side, passing over the origin of 

 the wings : wings hyaline, a little dusky, yellowish at base : scutel 

 yellow ; pectus black, with a whitish band before : feet yellow- 

 ish ; tarsi black : abdomen pale yellow, tip fuscous. 



Length seven-twentieths of an inch. 



The proboscis and palpi are much elongated. 



SAPKOMYZA Fall. 



1. S. CONNEXA. — Pale honey-yellow; head whitish. 

 Inhabits Indiana. 



Head whitish : antennae pale honey-yellow, terminal joint 

 rounded: eyes greenish, somewhat gilded: [178] thorax and 

 scutel honey-yellow : wings with a slight yellowish tinge : tergum 

 paler than the thorax : feet white. 



Length three-twentieths of an inch. 



Closely resembles S. Jlava Linn., of Europe, but is much larger. 

 The S. Jlava is also an inhabitant of this country. 



2. S. BiPUNCTATA. — Yellowish : wing with spots and costal 

 margin fuscous. 



Inhabits Mexico. 



Body pale honey-yellow : scutel with two black points on the 

 posterior edge : wings hyaline ; costal margin beyond the post- 

 costal nervure, and extending in breadth a little over the sub- 

 costal nervure, fuscous ; near its tip it extends into the wing so 

 as to form a spot on the externo-medial nervure, this nervure and 

 1829.] 



