1913] North American Dipterous Genus Neurigona 55 



base ; tarsi scarcely hifiiscated at tips ; front tarsi longer than their 

 tibias; front metatarsi little more than one-half as long as their tibia; 

 middle metatarsi two-thirds as long as their tibiae; second joint of hind 

 tarsi longer than first. Wings grayish hyaline, veins yellowish brown; 

 posterior cross-vein less than twice its length from the wing margin 

 measured on fifth vein; fourth vein gradually approaching third, ending 

 before the apex of the wing, not far from the tip of third vein. 



Female: Agrees with the male in most of the characters given, 

 except in the following points; there are several black bristles near the 

 tip of the front coxag ; abdomen with a row of black bristles on the hind 

 margin of each segment; fourth and fifth segments of the abdomen, and 

 the middle femora without cilia. 



Described from four males and four females in the collection 

 of the American Entomological Society, taken at Alamo- 

 gordo, N. M., May 8-15, 1902. Type No. 5258. 



Note. — I place this species in this genus for the present, but 

 it differs from the other species of the genus by having the 

 flattened space before the scutellum less distinctly defined; by 

 the greater development of the appendages of the hypopygium;. 

 and by the bristles on the outside of the middle coxse, and near 

 the tip of the middle and hind femora; also the abdomen of the 

 male is shorter and stouter than in most species of the genus. 



27 Neurigona tibialis n. sp. 



Figure 27. 



Thorax yellow, with more or less greenish gray on the dorsum; 

 abdomen yellow with black bands ; hypopygium yellow, and very small ; 

 front tibiae with a row of bristles above ; wings with the third and fourth 

 veins nearly parallel. Length 2)4 mm. 



Male : Face and palpi with white pollen, the fonner very wide for a 

 male; antennae yellow, first joint short and with three or four hairs 

 above; third joint missing; front and occiput dark greenish gray, with 

 white pollen; post-vertical bristles and some of the upper orbital cilia 

 black, the lateral and lower orbital cilia whitish. Thorax yellow, with 

 dark greenish gray on the center of the dorsum, which almost forms 

 three broad vittse, lateral ones abbreviated in front, and all somewhat 

 united; pleurse with a black spot above the middle coxse, and another in 

 front of the halters; scutellum and metanotum dark greenish gray, 

 the former yellowish below; acrostichal bristles rather long but scatter- 

 ing, forming two poorly defined rows. Abdomen yellow, incisions black 

 on the dorsum, this black extending forward so as to almost connect 

 along the center of the dorsum on the second, third, and fourth seg- 

 ments; fifth segment all black on the dorsum and with a greenish 

 luster; venter yellow; hypopygium dark yellow, very small, and with 

 two pair of short, slightly hooked appendages. Legs pale yellow; front 

 coxae with pale yellow hairs and bristles, the larger bristles blackish in 

 certain lights; middle coxae with black hairs and bristles, one of the 



