Horn. ] 560 [April 19, 
Occurs usually under bark from Alaska to San Diego and 
Arizona, and not common. 
Rh. costata Horn, Proc. Am. Ent. Soc. 1867, p. 293. 
This species resembles in all essential characters the pre- 
ceding and differs in having the thorax rather deeply sinu- 
ate posteriorly, the hind angles acute and prominent. Length 
ot inch; 8.5 mm. 
In both species the frontal margin is acutely serrate. 
Occurred at Gila Bend Station, Arizona. The measure- 
ment previously given by me is a little too great. 
ANCHOMMA Lec. 
Antenne inserted under the margin of the front, eleven-jointed, not 
retractile, moderately stout, slightly flattened, joints perfoliate, sparsely 
clothed with scale-like hairs ; first joint short, obconical, second transverse, 
third as long as the next two together, four to nine transverse, equal, tenth 
somewhat larger, eleventh smaller and narrower than the tenth, truncate 
at tip. Head horizontal, oblong, sides parallel at middle, gradually nar- 
rowed at apical third, posteriorly rather suddenly narrowed. Eyes small, 
flat, divided by the side of the head, upper portion linear, lower portion 
very small. Mentum oval, supported by a distinct peduncle; sides of 
gene triangularly prolonged in front and continuing posteriorly in a ridge. 
Mavxille not concealed, palpi moderately long, last joint longer than the 
preceding, truncate at tip. Labrum not visible beyond the clypeus. An- 
terior coxe small, moderately distant, less prominent than the prosternum. 
Posterior coxee separated by a quadrangular process arcuate in front. Legs 
slender, tibiv fimbriate at tip with short spinulose hairs, without spurs. 
Tarsi short, sparsely hairy beneath, first three joints gradually decreasing 
in length, fourth joint as long as the first three and with stout claws. Ab- 
domen with first three segments gradually shorter, fourth very short, fifth 
as long as third. 
A. costatum Lec. Proc. Acad. 1858, p. 63; Journ. 1858, pl. 1, fig. 18. 
Form elongate, color variable, piceous to pale brown, opaque. Head 
granulate, front finely carinate, sparsely clothed with yellowish scale-like 
hairs. Thorax very little longer than wide, apex and base equal, sides 
very feebly arcuate, margin acute, disc with three parallel costee near the 
middle the central finer, surface as in the head. EHlytra with the suture 
moderately elevated, and with three discal coste and margin acutely 
prominent, intervals biseriately coarsely punctured. Body beneath coarse- 
ly but sparsely punctate, sparsely clothed with scale-like hairs. Length 
.16 inch; 4 mm. 
Occurs from San Diego to Owen’s Valley, California, and 
rather abundant in the latter locality. 
