SYNOPSIS OW NORTH AMERICAN 8YRPHID.E. 25 



cept a blackish ring, basal half and extreme tip of the middle tibiie, first 

 three joints of front and middle tarsi, and the second and third joints, 

 Tvith the tip of the first of the hind tarsi, luteous; hind coxse armed 

 with a slender process, dilated and compressed toward the end; hind 

 metatarsi a little iucrassate. Wings, except the basal third, cinereous, 

 stigma subfuscous, small cross- vein from the base of the discal cell, and 

 the last section of the fourth vein from the margin of the wing, less re- 

 mote than in P. nigribarha, P.femoraUs, etc. — Translation of original. , 

 Type specimen compared. The singular long, slender process on the 

 hind coxne will at once render the species distinguishable. 



Pipisa salax. 



Piinca salax Loew, Centur., vi, 39. 



Rabitat. — Pennsylvania (Lw.)! 



$ . Black-bronze, white pilose ; frontal triangle, anterior half of the 

 vertical triangle and posterior margin of the eyes black pilose; antennae 

 black, below red ; legs black, the knees, base of front tibise, the middle 

 tibiae, except a fuscous preapical ring, and the basal joints of the front 

 tarsi, luteous. Wings, except the basal third, luteous cinereous. Length 

 6.0'"'" ; of wings 5.5 to 6°^™. 



Block-bronze, moderately shining, white pilose; eyes clothed with 

 minute black pile, below with white pile ; frontal triangle, and the ver- 

 tical triangle, except the posterior part, black pilose; antennae black, 

 below obscurely reddish; third joint oblong ovate; occiput white pilose, 

 posterior margin of the eyes black ciliate; abdomen briefly black pilose, 

 the first segment, the lateral margins of the remaining segments, the 

 usual metallic spots, and the posterior part of the fourth segment white 

 pilose; hypopygium much longer than in other species; legs black, 

 the knees, basal third, or half of the front tibiae, middle tibiae, except a 

 very broad preapical ring, first joint of the front tarsi and first two 

 joints of the middle tarsi, luteous, second joint of the front tarsi usually 

 reddish ; hind metatarsi a little thicker than the following joints. Wings 

 cinereous, basal third more purely hyaline, stigma subfuscous. 



Type specimen compared. 



Pipiza nigribarba. 



P'wiza nigribarba Loew, Centur., vi, 40. 



RaUtat. — New York (Lw.) ! 



$ Black-bronze, white pilose; frontal triangle and face black pilose j 

 antennae black; legs black, the knees, base of front tibiae, first three 

 joints of middle tarsi and the intermediate joints of front and hind tarsi 

 luteous, first joint of hind tarsi strongly incrassate ; wings, except the 

 basal third, cinereous, the last section of the fourth vein angulated. 

 Length of body 7™™; of wings 6.5™™. 



Black-bronze, moderately shining, white pilose. Eyes thickly clothed 

 with blackish pile; frontal triangle and the anterior half of the verti- 

 cal triangle black pilose. Antennae black ; third joint oblong, on the 



