204 DIPTEKA OF NORTH AMERICA. [PART II. 



middle, there are a few long black bristles, and between these and 

 the tip of the tibia, some long, curly black hairs. The hind tibise 

 are much stronger than the middle tibias, their first half is stouter 

 than the second and the. front side before the tip is armed with a 

 strong black bristle. Tarsi plain, their joints of decreasing length, 

 the first joint of the middle tarsi with a few bristles. Halteres 

 brownish-black. Wings blackish, all their veins broadly margined 

 with black ; the margins of the costa and of the first four longitu- 

 dinal veins are entirely confluent, so that the anterior part of the 

 wings appears altogether black ; upon the middle of the posterior 

 transverse vein and upon the curve of the last segment of the 

 fourth longitudinal vein there is a black spot ; the costal cell is of 

 a dark brown color. 



Female. The only female which I possess? is^not as well pre- 

 served as the described male, especially the characters of the face 

 cannot be recognized with certainty ; I -would therefore recall the 

 circumstance, that the face of most of the females of Scellus is 

 less yellow than in the males. The first joint of the antennae in 

 the female is considerably shorter than that of the male. Fore 

 femora and fore tibiae less stout, though the tip of the latter has 

 also a dentiform, but less stout elongation ; their under side has 

 no excision before this tooth and the front side of the tibice no 

 thorn. Middle femora not curved, on the larger half of their under 

 side with a few sparse bristles. Middle tibia? plain, upon the first 

 half with a considerable number of black bristles, upon the latter 

 part of the posterior side without the curly hairs which are found 

 in the male. Hind femora plain, slender, towards the tip but 

 very little stronger, upon the second part of the under side with 

 about six rather strong black bristles. Hind tibiae without the 

 strong bristle which, in the males, exists at the tip of the front 

 side. 



Hob. Middle States. (Osten-Sacken) ; Illinois. (Le Baron.) 



2. S. spininianus ZETT. and 9 Thoracis dorso obscure seneo, 

 albido-pollinoso, opaco, abdomine ex viridi cupreo, nitido, halteribus 

 subfuscis, alis nigris, basi et costse dimidise limbo subalbidis, margine 

 postico toto cinereo, lamellis analibus maris albis, basim versus infra 

 nigro-marginatis, apicem versus flavis, in surarao apice puucto fusco 

 notatis. 



The upper side of the thorax dusky bronze-colored, with whitish dust ; 



