AMERICAN DIPTERA. 165 



only being yellowish; wholly light gray pruinose, a trifle darker upon 

 the dorsum where there are one median and two lateral brown pruinose 

 stripes which are very distinct in good specimens. Of the two strong 

 bristles on either side of the dorsum, the one before the base of the 

 wing is white, the one further back, black. Halteres dark, with paler 

 peduncle. Abdomen black, brownish pruinose, the first segment and 

 both ends of the others grayish pruinose; the posterior margin of the 

 first with a row of stout black bristles. 



In a greased specimen the posterior margin of segment 3 and both 

 ends of segments 4-5, and the extreme base of segment 6, all yellowish- 

 red; the genetalia of all the specimens in part reddish. Legs yellowish; 

 the tips of the front and middle femora above black, their tibias with 

 a black line down their anterior side; hind femora whitish on the slender 

 basal portion, yellowish-brown on the swollen portion, the brown color 

 of the latter extends in a narrowing line nearly to the trochanter along 

 the anterior and posterior sides of the white slender basal half; hind 

 tibiffi whitish above and before, but very dark brown on the inner and 

 outer sides, especially so upon the distal half; apices of all the tarsal 

 segments blackish, the last segment almost wholly black. Claws black, 

 empodia present, about one-half as long as the claws. Wings hyaline, 

 veins strong, black, paler at base of wing, the second posterior cell 

 much longer than the third and with its base nearer the base of the 

 wing than that of the second submarginal; the fourth posterior with 

 a short peduncle. 



Type. — U. S. N. M.; Cat. No. 794G. Type series consists 

 of two males and two female specimens. 



Habitat. — Colo. (Morrison) ; Rio Rindoso, White Mts., N. M., 

 alt. about 7,()00 ft. (Aug. 2, C. H. T. Townsend) ; Cloudcroft, 

 N. M. (June 18, 19, Am. Ent. Soc. Phil.). 



Leptoga.ster iiicisiiralis. 



Leptogaster incisuralis Loew, Cent., II, 1862. 



(^ 9 • — Length 10-12.3 mm. — Small yellowish species. Thorax red- 

 dish, white pruinose, on the thoracic dorsum with a very large black 

 spot placed with the stripes; abdomen yellowish, with polished black 

 rings, legs pale straw colored, the obsolete rings of the hind femora a 

 little darker; wings hyaline, fourth posterior cell with a short peduncle. 



Face white pruinose, mystax of same color; antennae reddish, the 

 third segment elongate oval with a darker style of about the same 

 length; occiput sordid yellow pruinose with yellowish bristles; pro- 

 boscis deep brown. Thorax reddish, thinly white pruinose; the stripes 

 of the dorsum very broad, running together into a very large black 

 spot, the whole dorsum being more brownish pruinose than the pleurae 

 which are reddish above, black below, but wholly whitish pruinose. 



TRANS. AM. ENT. SOC., XXXV. MAY, 1909. 



