NORTH AMERICAN COLEOPTERA. 
323 
find any well marked secondary sexual characters. One specimen, 
seemingly a male, has the prosternum somewhat more opaque and a 
little more pubescent. 
Varmtiom . — The usual variations dependent on abrasion must be 
expected here as elsewhere. While the vast majority of specimens 
have the antennce serrate beginning with the fifth joint, one in my 
cabinet begins at the fourth, that is, the fourth joint more nearly 
resembles the fifth than the third. Such cases as this must be classed 
as abnormalities, and are very confusing to a systematist, or to one 
attempting to determine sjiecific names with but little material. 
Hab . — Canada to North Carolina, westward to Illinois. It is not 
recorded from the New England States, but probably occurs there. 
A. piitilliiM Say. — Form nearly of subcinctus ; dark olivaceous bronze, mod- 
erately shining. Antennae scarcely attaining the middle of the thorax, piceous, 
serrate from the fifth joint; head convex, with a feeble occipital impression, 
front s])arsely indistinctly punctate, slightly alntaceous. Thorax one-third wider 
than long, sides regularly arcuate, margin sinuous, hind angles rectangular 
without trace of carina; disc convex, with a feeble linear median impression, 
lateral depressions deep along the side, surface transversely strigose, but more 
evidently punctate near the apex; scutellum transversely carinate ; elytra ex- 
tremely little sinuate at middle, apices rounded, serrulate ; disc slightly depressed 
at middle, a feeble basal fovea, on each side a suhcostiform elevation, between 
which and the suture on each side the elytra are vaguely channeled, surface 
imbricate, hut not closely; body beneath usually darker, hut more shining than 
above; prosterual lobe subtruncate, sometimes feebly emarginate, intercoxal 
process relatively broad, obtuse at apex ; propleurae comparatively smooth ; 
metasternum at sides rather finely punctate and substrigose. Abdomen sparsely 
punctate over the entire surface and faintly alntaceous ; pygidium very indis- 
tinctly punctate, not at all carinate; claws broadly toothed at middle. Length 
.12 inch. ; 3 mm. 
Male . — Front greenish, more opaque and more closely sculptuTed. 
Prosternum more closely punctate along the middle and slightly pu- 
bescent. Abdomen simple, not roughened at base. 
Female . — Front aeneous, more shining and more sparsely punctate. 
Prostern u in not pubescent. 
Variations . — The color is very constant. The discal cosUr of the 
elytra vary considerably in their distinctness, and are sometimes 
nearly absent. In the outline of the upper surface, when viewed 
laterally, some are nearly straight, others quite arched. 
This species is the smallest found in the Atlantic region proper, 
and is remarkable in having the lower angle of the eve acute. 
Hab . — Canada (Pettit), Illinois, Indiana (Say). 
