SYNOPSIS OF NORTH AMERICAN SYRPHIDiE. 217 



broader towjirds the middle, coucave iu frout aud directed backwards and 

 outwards, but not reaching the sides, tlie sides of the segment narrowly 

 yellow, with yellow pile, the black opaque, except a posterior metallic 

 cross-band, broadest in the middle; third segment similar, except that 

 the spots are loss narrowed outward, and the anterior margin is nar- 

 rowly shining ; fourth segment like the third, except that the yellow 

 spots are broader, shorter, and more oval, the metallic of the front bor- 

 der narrower and contined mostly to the sides ; fifth segment in the 

 fpmale with the spots small and nearly rounded. The posterior segments 

 margined with yellow behind aud clothed with yellow pile, most abun- 

 dant on the last segment. Venter black, shining, with narrow yellow 

 hind margins to the segments. Legs light yellow, the immediate base 

 of all the femora (on the hind pair the inner side for nearly a third of 

 their length) and the last three joints of all the tarsi black; the fore 

 and hind tarsi on their first two joints and the tip of the hind tibise red. 

 Wings dark brown in front, lighter beyond the cross-vein the posterior 

 l)art hyaline. 

 Twelve specimens, Connecticut, Massachusetts, and Pennsylvania. 



CRIOPRORA.* 



CHoprora Oston Sacken, Cat. Dipt., 251, note 241, 1878, 



Large, black species, thickly or long pilose. Head not broader than 

 the thorax. P^yes bare, sub -contiguous. Antennae situated below the 

 middle of the head in profile, the first two joints a little elongated, the 

 third obliquely oval ; arista bare. Face laterally compressed, forming 

 a rounded ridge in the middle, on the upper part sometimes sharply 

 ridged, produced nearly forwards, more or less snout like, gently con- 

 cave from antenna' to tip, the end notched. Cheeks not broad, the 

 lower border nearly at light angles to the plane of the occiput. Tho- 

 rax rather short and broad. Abdomen oval. Legs stout, the hind 

 femora more or less thickened, with spines below; in the male the hind 

 coxffi sometimes tuberculate and the femora and rhe tibiie bent. Mar- 

 ginal cell of wings open ; third longitudinal vein nearly straight; cross- 

 vein beyond the middle of the discal cell and oblique. Type of genus 

 C. alopcx O. S., Xorth America. 



TABLE OF SPECIES. 



1. — Dorsum of thorax clothed with thick yellow, or rcfldish-yellow pile, ou the pleu- 



r;T.' black ; wings with brownish clouds along the veins 2 



Dorsum of tborax clothed withlong, grayish or yellowish-gray pile, on the ])li'U- 



nc vellowish-white; abdomen deeii bluish-metallic . . } ■' ° 



( cyanella 



2. — Front iu female broad, with yellow ])i]e ; hind femora somewhat incrassate, 



alopex 



Front in female clothed with Ijlack pile ; hind femora thickened, in nuile much 



more so and curved femorata 



KpioS, a ram ; npwpcc, front. 



