252 long's second expedition. 



THEREVA Latr. [370] 



T. frontalis. — Black; thorax witli two yellow vittae ; ter- 

 gum annulate with yellow. 



Inhabits North-west Territory. 



Head beneath with white hair ; antennae, proboscis, and palpi 

 black ; front and vertex dusky yellowish, with a large, deep black, 

 glabrous, polished, transverse, undulated spot j thorax black, with 

 two yellow lines, or yellow with three black lines ; wings hyaline, 

 tinged with dull yellowish ; nervures fuscous, slightly margined, 

 and with a carpal spot ; scutel yellowish, with a dusky basal spot ; 

 tergum glabrous, polished, the posterior margins of the segments 

 bright yellow, wider upon the sides ; pleura and pectus glaucous, 

 the latter hairy; poisers whitish; with a blackish capitulum; feet 

 black; tibia excepting at tip dull testaceous; venter cinereous, 

 changeable, second and third segments with yellowish posterior 

 margins. 



Length more than half an inch. [ 371 ] 



ANTHRAX Latr. 



1. A. ALCYON. — Wings brown, a hyaline spot near the middle, 

 another at tip in which are two curved brown lines. 



Inhabits North-west Territory. 



Body black, with pale fulvous hair ; head yellowish-white, 

 hairs above the antennae black ; tip of the hypostoma prominent, 

 and with black rigid hairs ; antennae black, basal joint yellowish 

 with black hairs ; vertex black ; occiput with a very profoundly 

 impressed line above ; scutel piceous ; wings dusky, pale brown 

 on the disk, an obsolete, small, subhyaline spot between the mid- 

 dle and the base ; a large, subtriangular, hyaline spot near the 

 middle, a small portion of which is cut off by a nervure ; tip with 

 a large, subquadrate-oval, hyaline spot, the two arcuated ner- 

 vures that pass across this spot are margined with blackish ; cen- 

 tral cellule widely bilobated at tip, lobes equally approaching the 

 inner margin, a nervure passes from between the lobes to the 

 edge of the wing, an abbreviated nervure passes from the lobe 

 nearest the base, half way to the inner margin, and another ner- 

 vure connects this lobe with the third nervure so as to form an 

 additional cellule ; feet yellowish ; tarsi black ; venter pale, two 



