292 
GEO. H. HORN, ISr. 1 ). 
tiiral edge is slightly elevated ; basal depressions distinct; surface with a densely 
imbricate sculpture; body beneath usually bluish, more shining than above; 
prosternal lobe obtuse, vaguely emarginate, the intercoxal process gradually nar- 
rowed and acute at tip, propleui'se scabrous or subgranulate ; metasternum coarsely 
punctate ; abdomen punctate, more sparsely along the middle, quite coarsely along 
the side, the first segment quite rough ; pygidium coarsely punctate, indistinctly 
carinate; tarsi slender, the first joint of the hind tarsi nearly half as long as 
thetibiic; (daws similar on all the feet in both sexes. Length .16 — .22 inch.; 
4 — 5.5 mm. 
J/a/e . — Form more slender, sometimes tilmost linear; front flatter, 
more densely punctured ; hind angles of thorax less distinctly cari- 
nate ; prosternum densely, finely punctate, finely pubescent, the pu- 
bescence usually extending along the median line of the body to the 
end of the second ventral segment ; first two ventral segments vaguely 
sulcate on the median line. Inner apical angle of all the tihiie 
spiniform and incurved. 
Female . — Form stouter, usually with more evident leneous surface 
lustre ; front slightly more convex, more coarsely, but less closely 
punctate, the occipital impression extending slightly downward ; hind 
angles of thorax (piite distinctly carinate ; prosternum much more 
sparsely |)unctate, not hairy ; first two ventral .segments not im- 
]>ressed and with smoother scul])ture. 
Variations . — The most striking structural variation is the hind 
angles of the thorax. The sexual variation has already been re- 
corded, but s])ecimens are before me as completely deprived of carina 
as any species in our fauna, not only males but females also. The 
smaller and less developed males have the ventral sexual characters 
less pronounced, so that the pubescence along the median line be- 
comes less distinct and the sulcus of the first two ventral segments 
almost entirely disappears. The color variations are not great, the 
males, however, are in a great part dull bluish, while the females are 
slightly greenish or cupreous. 
As this is a common and well known species, much space has been 
given to its description as a means of comparison for other species. 
Say’s A. geminaius is undoubtedly the female (T this, suhsecpiently 
described by him as otiosus. The former name has priority by sev- 
eral years, but the latter name is retained from its having acquired 
general acceptance, and from the fact that both belong to the same 
author and no injustice is done. This is clearly one of those cases 
in which the law of priority should yield to that of convenience. 
Habits . — Feeding on Oak shrubs (Blanch. Ent. Am. v, p. 32). I 
think it has been reared from Hickory twigs by Dr. LeConte. 
