5© KANSAS UNIVERSITY QUARTERLY. 



Apthorthus townsendii n. sp. 



Female. Face thinly dusted with white; front bright green, ocellar 

 bristles yellow, the cluster just behind these minute, white; bristles of 

 the sides of the front yellow; antennae black, hairs of second joint 

 brown; cilia of inferior orbit white, thorax bright green with a thin 

 coat of white dust, especially about the edges, the bristles long and 

 strong, brownish yellow in color, those of the central dorsal region 

 more blackish. Pleurae green, with whitish dust; halteres and tegulae 

 as in nigripes: scutellum with a large and a small pair of yellow 

 bristles. Abdomen golden green, witli short yellow hairs all over its 

 dorsal surface. Fore coxae yellow with coarse yellowish-white hairs; 

 middle and hind coxae black, with yellow tips and white hairs; femora, 

 tibiae and tarsi yellow, the last toward the tij) blackened, especially the 

 hind ones. The hairs of the legs are few, short and i)ale. AV'ings 

 hyaline, venation as above. 



One female. .\/tec, Arizona. July 21 (Townsend). 



Length, 4 mm.; of wing, 3.5 mm. 



LEPTORHETHUM n. gen. 



(Itjitiis, iKiriMw; iliithdx, lac'i'). 



Head wider than thorax; face long, narrow; antennae as in Psiiopus, 

 arista dorsal; front scarcely at all excavated, the lateral bristles small, 

 acrostichal bristles in two rows; scutellum with a large inner and a 

 small outer pair of bristles. Abdomen of male somewhat clavate, the 

 hyi^opygium sessile, but little visible. Wings narrowed at base, sixth 

 vein absent; third longitudinal vein curved forward at the tip; fourth 

 vein fi^rked as in Psilopus. 

 Leptorhethum angustatum n. sp. 



Male. Antennae, proboscis, coxae and legs yellow; cilia of tegulae 

 yellow; eyes almost contiguous on the middle of the face, thorax 

 bright green above; abdomen green, venter and basal segments 

 largely yellow. 



Length, 2 mm.; of wing, 2.2 mm. 



One male, St. ^'incent, West Indies (H. H. Smith). 



A fuller description of this species will appear in an extensive 

 paper on the West Indian Diptera now in preparation. 



