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



bristles at base on postero-ventral surface ; hind tibia with two 

 short antero-ventral, five or six short stout antero-dorsal, and 

 three or four slender postero-dorsal bristles; both mid- and 

 hind tibise with several strong curved apical bristles; tarsi 

 shorter than tibi?e. Costal thorn short; outer cross-vein 

 straight. 



Type, male, 4 mm. long, No. 534, C. A. S., Salada Beach, 

 San 'Mateo County, Calif., April 21, 1918; E. P. Van Duzee, 

 collector. 



This species has the head less elongated than has the 

 female of the genotype {protubcrans Malloch), but the other 

 characters agree very closely with those of that species and it 

 may really prove to belong to the same species. 



9. Hydrophoria seticauda, new species 



Male. — Deep black. Face, orbits, and cheeks with white 

 pruinescence. Thorax indistinctly trivittate ; abdomen with a 

 uniformly broad dorso-central vitta which covers about one 

 fourth of the dorsum : wings slightly brownish ; calyptrge 

 white ; halteres yellowish. 



Eyes separated by a little less than width across posterior 

 ocelli ; arista with its longest hairs not longer than width of 

 third antennal joint : parafacial at base of antenna as wide as 

 third antennal joint, not narrowed below. Presutural acros- 

 tichals weak, irregularly two-rowed : scutellum broader than 

 long. Processes of fifth sternite very broad, very incon- 

 spicuously haired on surfaces, their inner margins with a 

 fringe of long hairs. Mid-femur with two or three antero- 

 ventral bristles; mid-tibia with an antero-ventral bristle; hind 

 femur with a series of widely spaced postero-ventral bristles; 

 hind tibia with four or five bristles on each of the following 

 surfaces : antero-ventral, antero-dorsal, and postero-dorsal, 

 the posterior surface with a few setulose hairs on basal half. 

 Costal thorns of moderate size. 



Female. — Frontal bristles strong. Genital thorns distinct. 



Length, 6-7.5 mm. 



Type. male. No. 535. C. A. S., Huntington Lake, Calif., alt. 

 7000 feet, July 5, 1919 (F. C. Clark, coll.), and allotype. 



