270 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



coxae and femora black ; fore tibiae blackish ; middle and hind tibiae yellow 

 with black hairs, the latter with a row of yellow hairs below and rather 

 long numerous yellow bristles above, the bristle at tip black; fore tarsi 

 yellowish, first joint a little compressed and considerably widened at tip, 

 second and third joints much compressed, second about as long as wide 

 with a tliumb-like projection above at tip; third much expanded upwards; 

 fourth and fifth minute, black or partly black ; middle and hind tarsi in- 

 fu'scated towards their tips; their second joint one and a half times as 

 long as first ; tegulae, their cilia and the halteres yellow ; wings with 

 typical venation ; last section of fifth vein about as long as the cross-vein. 



Apparently there are six bristles on the edge of the scutel- 

 lum, but in the type specimen they are all broken off, leaving 

 only the scars to mark the places of insertion. 



Described from a single male taken at Los Amates, Guate- 

 mala, Feb. 18. 



Holotype, male, in collection of the author. 



18. Medeterus abruptus, new species 



Male: Length 2.8 mm. Face, front, and anterior part of the thorax 

 violet, remainder of the thorax and the abdomen shining green; first an- 

 tenna! joint black (other joints missing in type) ; lower orbital cilia yel- 

 lowish ; scutellum with four bristles ; hypopygium black with yellow ap- 

 pendages; coxae and fore and middle femora blackish; fore femora broadly, 

 middle narrowly, yellow at tip ; hind femora yellow, blackened a little at 

 base ; tibiae and tarsi pale yellow with yellow hairs and bristles, the bristles 

 at tip of tibiae and one small one near base of middle tibiae black; tarsi a 

 little infuscated at tip ; fore tarsi one and a half times as long as their 

 tibiae; first three joints a little compressed with a fringe of small black 

 hairs above; first joint nearly as long as the three following taken to- 

 gether; third joint abruptly narrowed to a slender projection to which the 

 fourth joint is attached; fourth small but slightly swollen; fifth slender; the 

 projection at tip of third joint together with the fourth and fifth joints 

 form a very slender tip to the fore tarsi; second joint of hind tarsi nearly 

 twice as long as the first. Tegulae their cilia and the halteres yellow. 

 Wings with typical venation ; veins and costa yellowish ; last section of fifth 

 vein only sHghtly longer than the cross-vein. 



Described from one male taken at Pt. Barries, Guatemala, 

 March 3. 



M. planipes, Uavipes and abruptus are remarkably alike in 

 appearance but differ widely in the formation of the fore tarsi. 



Holotype, male, in collection of the author. 



