48 Annals Entomological Society of America [Vol. VI, 



tarsi about three-fourths as long as their tibis, and about one and one- 

 fourth times as long as the remaining joints together; second and third 

 nearly equal ; fourth and fifth fringed on each side with long black hairs, 

 which form a fiat oval tip to the tarsi, this tip a little longer than wide; 

 fourth joint except base, and fifth black; first joint of hind tarsi a very 

 little longer than the second ; middle metatarsi about three-fourths .as 

 long as their tibiae. Tegulaas, their cilia, and the halters pale yellow, the 

 latter with a brown dot on one side at the base of the knob. Wings gray- 

 ish hyaline; third vein slightly bent backward at tip; fourth vein bent 

 forward from just before the middle of the last section, but the tip not 

 very close to the tip of the third. 



Female : Agrees with the male except that the front tarsi are plane, 

 with the metatarsi a little shorter than their tibis, and more than 

 twice as long as second joint ; first and second joints of hind tarsi about 

 equal; the mesonotum often nearly all yellow, except the flattened 

 space before the scutellum. 



Redescribed from many specimens taken in the vicinity of 

 Buffalo, N. Y. This is the most abundant species of Neurigona 

 around Buffalo, I have taken nearly one hundred specimens the 

 past summer, the first on July 9th, and the latest on September 

 8th; the only other specimen I have seen is a male form Mt. 

 Tom, Mass., taken July 14th, and sent to me by Prof. C. W. 

 Johnson. Loew's Mon. gives Middle States as the habitat. 



Note. — Prof. Wheeler in his description of the male of 

 tentas mentions a row of hook-like spines along the lower 

 surface of the front tibiae, also curved spines on the front 

 matatarsi; I cannot detect these in our eastern specimens, 

 although there is a row of very minute bristles or stout hairs on 

 the lower surface of the front tibiae that I have not mentioned 

 in the description I have given above, because they are so 

 easily overlooked that they are of little value in separating the 

 species, but in the closely related western species that I am 

 describing under the name of pectoralis these bristles are a 

 conspicuous character. The males of these two species are 

 so nearly alike in general appearance that he may have con- 

 fused them. They may be separated by the front tarsi of 

 tenuis being nearly as long as their tibiae, while in pectoralis the 

 tarsi are much shorter than their tibiae; in tenuis also the front 

 legs are infuscated from, or before the middle of the tibiae, in 

 pectoralis there is no infuscation of the front legs except the 

 .enlarged tip of the tarsi which is black; pectoralis has the first 

 and second joints of the hind tarsi equal, while in tenuis the 

 first joint is a little the longest; the middle coxae of pectoralis 

 have yellow bristles which are not found in tenuis. 



