264 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Sei. 



veins rather closely approximated at their tips; last section of fifth vein 

 twice as long as the cross-vein; veins brown, becoming darker towards 

 the root of the wing. 



Described from four females taken by me at Los Angeles, 

 Cal., Apr. 27 and May 4, 1915. 



Holotype, female (No. 514), in collection of the California 

 Academy of Sciences. Paratypes in collection of the author. 



7. Medeterus nitidiventris, new species 



Male and female : Length 2 mm., of wing the same. Face and front 

 covered with gray pollen, face below the suture more blackish; antennae 

 black, small, third joint rounded, small, scarcely as wide as long; pro- 

 boscis rather small, black ; inferior orbital cilia pale ; thorax gray with a 

 median brown vitta which extends from the front nearly to the posterior 

 margin of the scutellum, in some females it is somewhat obliterated pos- 

 teriorly; pleurae black with gray pollen; acrostiohals in two rows; four 

 dorso-centrals inserted on minute brown dots; scutellum with one pair of 

 bristles ; abdomen black, shining, depressed, with gray pollen on the sides, 

 its hairs pale ; hypopygium rather slender, extending nearly to the base of 

 the venter, black with its appendages black or testaceous; legs black, knees 

 yellow; tibiae in the females sometimes yellowish brown; second joint of 

 the hind tarsi of the male about one and a half times, of the female one and 

 a fourth times, as long as the first; tegulae yellow with a narrow brown 

 border and pale cilia ; halteres yellow ; wings grayish hyaline ; veins brown, 

 a little yellowish at the root of the wing; last section of fifth vein one and 

 a half times as long as the cross-vein ; in the female there is a brownish 

 cloud at the base of the third vein which is sometimes very faint, in others 

 distinct but not as sharply defined as in cuneiformis. This cloud extends 

 along the third vein, more or less distinctly, nearly to its tip, tinging 

 nearly the whole of the cell between the second and third veins with brown. 



Described from one male and two females taken by me at 

 San Francisco, Calif., May 12, to 27, 1915. 



This species is very like cuneiformis but differs in hav- 

 ing the abdomen shining black, the legs wholly black except 

 the knees, and in having the brown cloud more diffused not 

 sharply defined as in cuneiformis. 



Holotype, male, and paratype in collection of the author. 



Allotype, female (No. 515), in collection of the California 

 Academy of Sciences. 



8. Medeterus obesus, new species 



Female : Length 2 mm., of wing 2.25 mm. Face and front blue-green, 

 shining, with but little pollen; antennae very small, black; arista about 

 apical ; proboscis small, black ; orbital cilia pale ; thorax bluish green with 

 purple reflections, rather thickly covered with brownish pollen, which is 

 more gray on the upper part of the pleurae; the space between the rows 



