NORTH AMERICAN COLEOPTERA. 
25 
In this species tlie elytra are colored very like gentilu. The more 
striking differences between it and the others of the group are suffi- 
ciently detailed in the table. 
Occurs in Missouri ; collected by Dr. S. V. Summers, Ohio (Blan- 
chard). 
C. perplexiis Horn. — Moderately elongate and convex, piceous-black, 
shining, sparsely pubescent, three basal joints of the antennse, legs and a humeral 
spot reddish yellow; antennse slender, feebly serrate; front rather flat, sparsely 
punctate; thorax distinctly longer than wide, nearly equally narrowed at base 
and apex, widest a little in front of middle, sides arcuate, distinctly sinuate in 
front of the hind angles, which are small, acute and distinctly divergent, the 
Carina distinct, disc convex, sparsely but equally punctate, median smooth line 
distinct; elytra elongate oval, widest at middle, humeri rounded, the disc striate, 
strise rather deep and coarsely punctate, the intervals convex, shining and very 
sparsely punctulate ; prosternum transversely impressed in front, the lobe short 
and obtuse, surface sparsely finely punctate at middle, more distinctly at the 
sides, propleura*, shining, a little more coarsely and less closely punctate than the 
sternum; metasternum a little more coarsely and closely punctate; abdomen 
more finely than this. Length 2.75 — 3.5 mm. ; .11 — .14 inch. 
This species resembles that variety of quadripmtvlatus in which 
the humeral spot alone is present, but it differs in having the thorax 
very obviously longer than wide, the elytral striie more coarsely 
punctate, and the intervals smoother. The hind angles of the thorax 
are sometimes tipped with yellow, but this is by no means frequent. 
The body is very feebly winged. 
Occurs in the District of Columbia, where it has been collected 
abundantly, at times, by Mr. Ulke. 
Group PECTORALIS. 
Prosternal sutures arcuate, convergent posteriorly, nearly twice as 
widely separated at the apical angles as at the coxae. Maxillary 
palpi not prominent, the last joint triangularly oval. Legs slender, 
the tibial spurs minute. Form at least moderately convex, body 
winged. Elytra either not at all striate, or those near the suture 
alone indicated faintly. Thorax without basal incisures, a smooth 
median line variably present. 
This group is equivalent to the second division, A A, indicated in 
the Monograph of Candeze. Those occurring in our fauna separate 
very naturally from the exotic forms by having the carina of the 
hind angles of the thorax short, while in those the carina is pro- 
longed nearly or quite to the anterior angles. 
TKANS. AM. ENT. SOC. XVIII. 
(4) 
FEBRUARY, 1891. 
