298 Annals Entomological Society of America [Vol. VI, 



teriorly than anteriorly, at highest part about one-third as high as eye, 

 marginal bristles distinct, 6-7, the anterior pair higher than vibrissa; 

 vibrissa strong; proboscis yellow; palpi black, distinctly bristled. Meso- 

 notum subopaque, gray-black, about one-third longer than broad; 

 lateral margins with indications of brownish color, but not yellow; four 

 pairs of long dorso-central bristles present, which are in parallel rows, 

 the anterior pair distinctly in front of suture; four irregular rows of 

 setulas between the dorso-centrals, which are carried to between pos- 

 terior pair; no distinctly differentiated bristles between posterior dorso- 

 centrals; pleurse marked as in longipennis; squamse yellow, fringe 

 brownish; postnotum and scutellum concolorous with disk of mesono- 

 tum. Abdomen elongate, shining black, with grayish pollinosity, only 

 the last segment with distinct, very narrow, yellow posterior margins; 

 ovipositor glossy black, base as long as last abdominal segment, seg- 

 ments with numerous short hairs; hypopygium of male rounded, with 

 two flap-like protruding, downward directed, apical organs. Legs 

 black, shining, knees distinctly, but narrowly, pale yellow; mid tibiae 

 without posterior bristles. Wings grayish, rather elongate, venation 

 almost as in longipennis. Halteres yellow. 

 Length, 3.5 to 4 mm. 



Type: (Male); Cat. No. 15570, U. S. N. M. 



Locality: Florissant, Colorado, (7,000 feet level) June 

 21, 1907, (S. A. Rohwer). Five specimens, two males and 

 three females. Taken amongst grass. There is a female 

 from Colorado in C. W. Johnson's collection and a male in 

 same collection from Eastport Maine. 



Food-plant unknown. 



24. Agromyza marginata Loew. 



Syn: Agromyza marginata Loew, Dipt. Amer. Sept. Indig. Cent. 8, 1869, 

 species 91. 



Male and Female: Frons pale lemon yellow, shining, center 

 stripe opaque black, deepest in color at anterior margin above lunule; 

 ocellar triangle distinct, black, margins narrowly yellow; orbits of 

 nearly equal breadth on their entire length, darkened anteriorly, four 

 orbital bristles anterior to front ocellus, these are on middle of orbits, 

 there are no additional hairs present on any of the specimens before 

 me; antennee brown, of rather less than normal size, dorsal bristles on 

 second joint of moderate size; third joint rounded, barely longer than 

 broad; arista brown, slightly swollen and tapering at base, almost 

 bare, reaching from its base to anterior ocellus in female, slightly 

 shorter in male; face brown, concave in profile, the lower margin, at 

 mouth, projecting slightly, center keel indistinct; cheeks yellowish 

 brown, short, gradually deepening from front to back, where they 

 are less than one-fourth the height of the eye; marginal bristles dis- 

 tinct, vibrissa strong; eye distinctly higher than long. Mesonotum 

 slightly longer than broad, glossy black brown; three pairs of dorso- 

 centrals present, the anterior pair weak, disk with niumerous distinct 



