360 ACADEMY OF NATURAL SCIENCES 



VOLUCELLA Geoff. Meig. 



1. V. VIOLACEA. — Dark violaceous ; hypostoma whitish. 

 Inhabits Mexico. 



Body blackish-violaceous : hypostoma dull honey yellow, with 

 small hairs reflecting whitish; thorax, each side, and scutel 

 paler : wings blackish at base ; this color is confined to the basal 

 cellules and the costal margin to the middle. 



Length % thirteen-twentieths of an inch. 



The eyes of the specimen are in contact on the vertex. 



2. V. POSTicA. — Obscure violaceous ; hypostoma whitish with 

 a lateral black line. 



Inhabits Mexico. 



Body blackish-violaceous : head whitish, tinged with obscure 

 yellowish : antennae fuscous : hypostoma with a black line each 

 side : orbits behind and above silvery : thorax each side and be- 

 fore the scutel, dull honey-yellow : scutel honey-yellow : wings 

 [167] hyaline, transverse nervures of the middle margined with 

 blackish : tergum yellowish-violaceous, darker on the tips of the 

 segments ; third and fourth segments with a small white spot on 

 each side at their bases : venter with a yellow disk : feet black- 

 ish ; tibiss dirty honey-yellow. 



Length half an inch. % . 



Viewed from before, the posterior segments of the tergum 

 have a hoary appearance, in consequence of having numerous 

 short hairs of that color. The eyes in the specimen are distant 

 on the vertex. 



3. V. MARQiNATA. — Black, head white; tergum with black 

 bands. 



Inhabits Mexico. 



Head white ; vertex black ; face with a black line extending 

 to the tip of the hypostoma : hypostoma with a line each side, 

 and all beneath black : orbits beneath white, behind glaucous : 

 antennae dark honey-yellow, seta very densely plumose, appearing 

 like a solid mass, black : thorax with a vitta on each side over 

 the wings, and two spots at base, yellowish white : wings with 

 the middle cross nervures margined with dusky : tergum pale 

 yellow, with a black dorsal vitta, and black posterior margins to 



[Vol VI. 



