AMERICAN DIPTERA. 161 



front and middle femora and their tibise, together with the hind tibiae, 

 with a dark brown stripe or Hne along their anterior surfaces which is 

 variable in extent, and, in some cases, lacking; tarsi brown, the first 

 segment, except its apex and the bases of the following segments below, 

 pale straw. Wings hyaline, basal third pale fuscous; second submarg- 

 inal cell short, narrower toward the apex, the second posterior but 

 little longer than the third, the fourth posterior with a long peduncle; 

 the anterior intercalary forms a sharp angle at its junctions with 

 the posterior cross-vein. 



Type.- — M. C. Z. A single male and female, each in a poorly 

 preserved condition. 



Habitat. — 111. (type); White Mts., N. H.; North Saugus 

 (July 12, 1906), Amherst (July 2-25), and Woods Hole (Aug. 

 4), Mass.; N. Y.; Jamesburg (July 4), Dunnfield, Delaware 

 Water Gap (July 8, 15), Pa.; Riverton (July 30), C. W. John- 

 son, N. J.; Douglas Co., Ks. ; Neb.; Ind.; Milwaukee (June 

 23), Wis.; Montreal, Canada. 



Readily distinguished by its clear glistening chestnut dor- 

 sum, the two polished black spots behind the transverse 

 suture, and by the white bloom of the lateral margins and 

 pleurae. The polished spots behind the transverse suture are 

 sometimes of the same color as the rest of the dorsum. De- 

 scribed from twelve specimens. 



Leptogaster brevicornis. 



Leptogaster brevicornis Loew, Cent., X, 23; 1872. 



9- — Length about 10 mm. — Dark brown species: the third segment 

 of the yellow antennas ovate and a little shorter than the correspond- 

 ing segment in other species, and shorter than its style. Hind femora 

 with a conspicuous dark brown ring. 



Face and mystax whitish; thorax brownish, the dorsal stripes, how- 

 ever, more obscure and covered with a light gray bloom. Abdomen 

 subpolished, toward the basal portion opaque, and covered with a gray- 

 ish bloom; segments 2-4 each with a subapical yellow ring, besides more 

 obsolete interrupted dull yellow rings on the bases of segments 3-5 

 above; vestiges of a median ring may be seen also on the second seg- 

 ment. Legs yellowish, the hind femora before the apex with a very 

 prominent dark brown ring; the other femora with a less distinct and 

 perfect one. Hind tibise brownish; the yellow basal third on both 

 sides with a dark line; the distal two-thirds brown with a reddish 

 tinge, and bearing a median j'^ellow ring. Wings subhyaline, slightly 

 tinged with yellow; veins dark brown; the second submarginal and 



TRANS. AM. ENT. SOC, XXXV. (21) MAY, 1909. 



