VOLUME 55, NUMBER 1 
43 
curved, somewhat compressed, bearing in both sexes a striking single-file 
comb of 18 to 25 blackish stout spinules on their outer posterior borders. 
The tarsi have slender claws, dilated at the base, with slender ungual ap¬ 
pendages the full length of the claws. 
Elytra .—Humeri are moderately prominent, the contour posterior to them 
slightly narrowed and depressed dorsally, then gracefully curving, wider 
behind the middle, the lateral edges only slightly recurved. Epipleurae are 
broad, parallel briefly, then abruptly narrowing, extruded to the bend of the 
elytra. 
The collection was made in November 1963 by Michael E. Irwin from 
flowers of Palofoxia and Stephanomeria. Thirty-seven specimens were col¬ 
lected south of Palm Springs, Riverside County, California; 19 in Coyote 
Canyon and 18 in Deep Canyon. I am pleased to name the species after Dr. 
Irwin for his numerous kindnesses to me in the past. The collection bears 
my numbers 2470-2506. 
Holotype .—Male, No. 2476, from Deep Canyon. Allotype: No. 2482, 
from Deep Canyon. Paratypes: 16 males and 19 females. 
The holotype and allotype are designated to be deposited in the type 
collection of the California Academy of Sciences. Duplicates are designated 
for the University of California collections in Riverside and Berkeley. 
Pristocelis volki, new species 
Size and shape .—The range from 2.1 to 2.7 mm length makes this the 
smallest species of Pristocelis. Sexes overlap in size, but the largest are 
females, and the smallest are males, thus reversing the sexual dimorphism 
from that of other Pristocelis. Bodies, parallel-sided, slender, about 2.5 
times longer than wide. In males the pronotum is much larger than in fe¬ 
males. 
Color .—In males, head pitch black, the color varying in its extent onto 
the face which is rufo-testaceous with black mandibles. Antennae, varying 
from pale amber at base to rufo-testaceous distally. Pronotum, with variable 
black, limited to a central spot, or a median line, or spreading, with testa¬ 
ceous lateral and sometimes anterior borders. Elytra, in both sexes, black 
with testaceous tips, the yellow variable in its forward extension. 
In females, the head is variable from ruddy to yellow testaceous, lacking 
a black occiput. Pronotum, the same as in the male except for one specimen 
which is all bright testaceous. 
The ventral sterna and legs are bright yellow-testaceous in both sexes. 
Pubescence. —The body is covered with one kind of fairly dense, closely 
decumbent short creamy-white hairs. Pronotal fringes of irregular longer 
slender hairs. Elytral fringes not distinctive from hairs on the back. Ventral 
