180 ENTOMOLOGICAL SOCIETY 



cluster of bristles and hairs in front of the halteres " that is, on 

 the hypopleura, agreeing in this respect with my specimens. 



An examination of a large series of North American specimens 

 belonging to nineteen different species in these two genera shows 

 that this character is equally marked in all of them, the hypo- 

 pleura being either quite bare, or else nearly covered with bristles 

 and hairs ; it will therefore be advisable to employ this character 

 in separating these two genera in place of the variable and unsat 

 isfactory characters taken from the antennae and wings which 

 have heretofore been employed for this purpose. 



Laphystia flavipes, n. sp. 



Black, the halteres, and femora and tibiae except their apices, yellow, 

 the hairs and bristles whitish; second joint of antennae about two-thirds 

 as long as the first, the third as long as the first two together, rather 

 slender, gradually tapering to the apex, the second joint of the style wider 

 than the first, only slightly longer than wide; head and body densely 

 gray pruinose, somewhat yellowish on the face, front and mesonotum, 

 the broad front portion of the abdominal segments two to six except on 

 the sides, and the narrow hind margins of the first five segments, polished ; 

 wings hyaline, the auxiliary, first vein and bases of the others, yellow, 

 remainder of the latter brown. Length nearly 10 mm. 



Montana and North Carolina. Two males collected by H. K. 

 Morrison. 



Type. No. 7950, U. S. National Museum. 



Laphystia limatula, n. sp. 



Differs iromjlavt'pes as follows : Second joint of antennae nearly as 

 long as the first, the third robust, of nearly an equal width; mesonotum 

 not gray pruinose except along the lateral and posterior margins, that on 

 the abdomen very thin, broad posterior ends of the last five segments 

 reddish yellow. 



La Luz,New Mexico. A male specimen collected August 23 

 by Mr. C. H. T. Townsend. 



Type. No. 7951, U. S. National Museum. 



Laphystia opaca, n. sp. 



Black, the halteres, bases of tibiae and of the hind femora, yellow, the 

 hairs and bristles whitish ; second joint of antennae about half as long as 

 the first, the third broad and only slightly tapering to the apex; head and 

 body densely grayish pruinose, three broad vittae on the mesonotum and 

 a subtriangular spot at middle of base of abdominal segments two to six, 

 polished; the median vitta of the mesonotum is on its anterior third; 

 wings hyaline; auxiliary vein and bases of the others yellow, remainder 

 of the latter brown. Length 8 mm. 



