82 Psyche [March-June 
the anterior distal quarter of the wing and in having the second 
basal cell shorter than the first. 
Chersodromia cana, n.sp. 
Female. Length 1.4 mm. Body and legs wholly black, more 
or less overlaid with white-gray pruinosity which is dense on 
the thorax except the sternopleural spot; all hairs white, all 
bristles short and black; halteres and palpi white. Front twice 
as long as width at bottom, face with coarctate sides, five times 
as long as narrowest width, two pairs of verticals, one of fron- 
tals; second joint of antennae nearly equal to the rounded third 
joint, style subapical, about twice as long as the third joint; 
proboscis retracted. Dorsum of thorax rather evenly covered 
with appressed white hairs, scutellum with two bristles and two 
lateral white hairs, one each of humeral, notopleural, propleural 
and intra-alar. Vestiture of abdomen sparse, last segment com- 
pressed. Middle tibiae with two extensor bristles, hind tibiae 
with two extensors near middle and three before tip, front tarsi 
shorter than tibia, the joints almost globular, the first joint not 
twice as long as wide. Wings milky white, no stigma, basal 
costal bristle black, all hairs of wing margin small and white, 
veins white on basal half and gray on apical half, costal ratio 
from humeral crossvein 8:3: 5:3, crossvein near middle of fifth 
vein. 
Holotype: Laguna Beach, California, 25 January 1935. 
In the European species, likewise, when the dorsocentral 
bristles are not developed the notal hairs are pale. Our species 
differs in having the legs completely black. The distinction 
between bristles and hairs is clearly indicated by the color. 
It is worth recording that a specimen of Chersodromia which 
I collected on the beach near St. George, Bermuda, on February 
1, 1934, appears to be identical with Ch. beckeri Melander from 
the Baltic Sea. Unfortunately the Bermuda as well as the Baltic 
specimens are known from females only. It may be that the 
discovery of males will enable a distinction to be made. 
Key to the American Species of Chersodromia 
1. Mesonotum shining black, no dorsocentrals ; pygidium about as large as the 
rest of the abdomen; legs blackish; halteres white. Cal. megacetes, n.sp. 
Body overlaid with grayish pollen 2. 
2. Hairs of mesonotum white, bristles black, no dorsocentrals; legs blackish; 
halteres white. Cal. cana, n.sp. 
