66 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 30 Ser. 



pair of dorsal vittse, one on either side of tlie single row of acrostichal bris- 

 tles. These vittse, fused in some specimens to form a single vitta, fade away 

 towards the middle of the thorax. In some lights the thorax has a mottled 

 appearance owing to large spots of thinner dust which reveal the metallic 

 green ground-color more distinctly. Abdomen flattened dorsoventrally and 

 pointed. Hypopygium completely concealed in a median cleft of the fifth 

 segment; the sternite of the fourth segment has its posterior edge bent into 

 a V, the apex of which projects slightly and is directed forwards. All the 

 segments of the abdomen covered with rather long snow-white hairs. Pleurae 

 and coxce with white dust thicker than elsewhere on the body, the white 

 hairs on the anterior and outer surfaces of the coxae very short and incon- 

 spicuous. Legs rather slender, metallic blue-green, dusted with white. 

 Tarsi black, all their claws and pulvilli enlarged, the latter white. Fore 

 femur with two irregular rows of black spines on its lower anterior surface. 

 These spines extend nearly the whole length of the femur. Fore tibia pro- 

 vided with a regular row of long tooth-like spines, the first of which at the tip 

 of the tibia is large and pointed and projecting at right angles to the long 

 axis of the tibia; the remaining teeth in the series gradually decrease in 

 length proximally and are inserted more obliquely. Wings hyaline. Veins 

 dark brown or black, with light yellow bases. Costa yellow to half way 

 between the tips of the first and second veins, becoming abruptly black at 

 this point. Venation normal, except that the tip of the third vein is rather 

 strongly bent downwards before reaching the costa. Halteres and tegulae 

 pale flesh-colored, the latter with white cilia. 



Female. Length 3.5-4 mm. ; length of wing 4.5-5 mm. Same as the male 

 in the coloration and in the spinulation of the fore femora and fore tibiae. 

 The abdomen is broad and flat, the sternites of the fourth and fifth segments 

 flattened and plain. 



Numerous specimens of both sexes from the following 

 localities: Palo Alto, Calif., August 6, 1894 (Leland Stan- 

 ford Jr. Univ.); Lusk, Wyo., July, 1895 (Univ. of Kansas 

 Collection); Las Cruces, N. M., August 23rd; Magda- 

 lena Mts., N. M., August, 1894 (A. W. Snow); Jackson- 

 ville, Tex. (C. W. Johnson) ; Douglas Co., Kansas (A. W. 

 Snow). I have taken this species in great numbers in 

 Wyoming during August. The specimens from different 

 localities vary in color, those from New Mexico having 

 more silvery dust than Calif ornian specimens. 



67. Hydrophorus agalma, sp. nov. 



Plate IV, Figs. 120 and 121. 



Male. Length 4.5 mm.; length of wing 4 mm. Palpi and face thickly 

 covered with silvery white dust, the former with white hairs, the latter dis- 

 tinctly narrowed above. Antennas black, of the usual shape, first and sec- 

 ond joints together longer than the third; base of arista rather thick, black 

 apical half attenuated, white. Front opaque brown, more cupreous behind. 



