NORTH AMERICAN COLKORTERA. 
327 
pubescence. Antennae short, scarcely reaching the middle of the thorax, piceous, 
strongly serrate from the fifth joint; head feel)ly convex, a vague median im- 
pression more evident in the female, surface rather roughly punctate-strigose. 
Thorax as long as wide (male), or a little wider than long (female), sides nearly 
straight 'J, , or slightly arcuate 9, hind angles rectangular, with a fine straight 
Carina, more evident in the J, margin sinuous; disc regularly convex, without 
median or lateral depressions, surface rather coarsely transversely strigose, with 
a pubescent space at sides, broadest behind, enclosing the carina; scutellum 
transversely carinate ; elytra scarcely sinuate behind the humeri, apices rounded, 
more acute and more distinctly serrulate in % ; disc with a very vague costa, 
between which and the suture, in a slight channel, is the pubescent vitta; sur- 
face moderately closely imbricate; body beneath geueous, with fine short pubes- 
cence; prosternal lobe obtusely rounded, the iutercoxal process rather broad, 
truncate at tip, propleurse punctate and pubescent; metasternum at sides closely 
punctate and somewhat strigose. Abdomen moderately closely finely punctate, 
denser at sides of first segment; pygidium sparsely punctate, not carinate ; claws 
dissimilar in the sexes. Length .22 — .24 inch. ; 5.5 — 6 mm. 
Male. — Front flatter, tlie median imprecision feeble. Thorax as 
long as wide, tlie sides nearly straight. Prosternuin roughly punc- 
tate, sparsely pubescent. Abdomen simple, the first segment rather 
rough at middle ; claws on all the feet cleft very near the apex, 
almost bifid ; tibite simple. 
Female. — Head more convex, the median impression deeper. Tho- 
rax a little wider than long, the sides moderately arcuate. Proster- 
num less rugose, scarcely pubescent. Abdomen le.ss rugose ; claws 
broadly toothed. 
Variation. — In this species, as in others already noted, there is be- 
tween the pubescence a whitish efflorescence, which makes the pu- 
bescence seem denser and whiter, but when this is removed by acci- 
dental moistening the reverse is produced. 
This species resembles jacobinm, of the preceding series, in form 
and color, but differs in the form of the antennm and the presence 
of the pubescent vitta. It resembles still mure blandus but that 
has no trace, whatever, of carina in the hind angles, and the proster- 
nal lobe is more distinctly emarginate. 
Hab. — Arizona, probably near Tucson. 
A. iiii|>exii!it u. sp. — Subcylindrical, slightly flattened above, dull cupreo- 
seneous, each elytron with three indistinct pubescent spots. Antennae not reach- 
ing the middle of the thorax, piceous, with slight aeneous lustre, serrate from 
the fifth joint; head broadly, but feebly coucave, with a median impressed line, 
surface closely punctate-strigose. Thorax scarcely wider than long, the sides 
very feebly arcuate, slightly sinuate near the hind angles, which are rectangular 
and distinctly carinate, margin sinuous; disc convex, with a median depression 
variable in distinctness, and when well marked with an impressed line at bottom 
