1913] North American Dipterous Genus Neurigona 47 



Female: Wings with the costa nearly straight, the cloud less dis- 

 tinct than in the male, the whole wing being tinted with brownish in 

 front of the third vein, and slightly clouded along the fifth vein; 

 front tarsi plain, otherwise as in the male. 



Described from four males and six females, from western 

 N. Y. and Ont. I took the males and five females near Buffalo, 

 N. Y., and one female at Kearney, Ont., July 8th; those taken 

 near Buffalo were captured between June 6th and loth. 



Note, — This species is closely related to arcuata, but may 

 easily be separated by its size, (this being the largest species 

 taken so far in North America) the form of the front tarsi, and 

 the wings, the latter being almost deformed. 



1 9 Neurigona tenuis Loew. 



Figure 19. 

 Saiicroptis tenuis Loew, Mon. N, A. Diptera ii, p. 228, 1864. Described from 

 the female. The male was described by Prof. Wheeler in the Proc. Cal. Acad. 

 Sci., ii, p. 73, 1899. 



Mesonotum green; abdomen yellow, with black bands; hypopygium 

 black, large; front tarsi about the same length as their tibia and with 

 an oval tip. Length 3>2— i mm. 



Male: Face and palpi white; eyes contiguous at the center of the 

 face; proboscis yellow; front and occiput greenish gray, sometimes 

 quite dark, thickly covered with white pollen; frontal bristles black, 

 orbital cilia and post-vertical bristles pale yellow; antennas yellow, the 

 third joint sometimes brownish, arista brown. Dorsum of the thorax 

 light verdigris-green, shining, dulled with thick grayish pollen, that 

 on the flattened space before the scutellum a little yellowish ; humeri and 

 more or less of the lateral edges yellow; pleurae greenish gray, with more 

 or less yellow below, in some specimens nearly all yellow, covered with 

 white pollen; scutellum green on the disk, with a rather wide margin of 

 yellow; metanotum greenish gray, becoming dark brown in some indi- 

 viduals, white pollenose. Abdomen yellow with wide black bands on 

 segments two, three, and four; those on the second and third narrowed 

 laterally so as to form nearly triangular spots; fifth mostly or entirely 

 black ; first more or less brown on the dorsum ; venter yellow on the basal 

 segments, more brown or blackish toward the posterior end; hairs of 

 the abdomen mostly black, with more pale hairs posteriorly, on the 

 fifth segment they are altogether pale; those on the ventral surface of 

 the fourth and hind part of third long; hypopygium black, basal part 

 somewhat shining but dulled with white pollen, apical part, and 

 appendages shining, polished. Legs pale yellow; front coxse long and 

 slender, with minute scattering hairs on the front side, and a few yellow 

 bristles near the tip ; middle coxae with a very few black hairs or bristles 

 near the tip, and a few yellow hairs at tip inside, these hairs curled 

 inwards ; hind coxffi usually blackened a little at tip on the inside ; mid- 

 dle and hind femora with a few bristles on the inside near the base, 

 those on the middle ones black, on the hind ones yellow; front meta- 



