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



Eyes densely hairy, separated at narrowest part of frons by 

 a distance a little less than width across posterior ocelli ; para- 

 facial as wide as third antennal joint, and over half as wide 

 as height of cheek, the latter with a glossy, strongly haired 

 area which covers all except a narrow strip of cheek along 

 eye-margin and a small patch behind vibrissge; arista almost 

 bare. Prealar absent ; intra-alar bristles both long ; presutural 

 acrostichals absent; hypopleiira bare. Abdomen as in H. 

 Jwiighi Malloch. Fore femur with a stout outer and a slender 

 inner preapical ventral thorn, the inner, or anterior, one 

 whitish; postero-ventral surface on basal half with numerous 

 bristles, many of them short ; fore tibia stout, except on basal 

 third where it is very slender ; mid-femur without strong ven- 

 tral bristles; mid-tibia with two antero-dorsal and four or five 

 postero-dorsal bristles ; mid-tarsus normal ; hind femur with 

 a stout straight short double ventral spine about one-fifth from 

 base, and four or five bristles on apical half of antero-ventral 

 surface; hind tibia with one or two postero-dorsal bristles, and 

 long hairs on apical half on all surfaces except postero-dorsal, 

 those on antero-dorsal extending almost to base. Venation as 

 in H. houghi. 



Type, male, 6 mm. long, No. 523, C. A. S., Fallen Leaf 

 Lake, near Lake Tahoe, Calif., July 15, 1915; E. C. Van Dyke, 

 collector. 



This species is most closely allied to occulta Meigen, but 

 may be separated from it by the larger size, different arma- 

 ture of the hind tibia and several other characters. 



2. Helina fuscomarginata, new species 



Female. — Bluish black, with distinct, but not dense grayish 

 pruinescence. Ocellar triangle shining; antennae and palpi 

 black ; thorax quadrivittate ; abdomen without markings ; legs 

 black; wings slightly grayish, cross-veins faintly infuscated, 

 veins black; calyptrse gray, with conspicuous black margins; 

 halteres black. 



Eyes pubescent; frons over one-third of the head-width; 

 each orbit with seven or eight bristles and many lateral setu- 

 lose hairs, most numerous anteriorly; face concave in profile;. 



