Horn.] OTA [April 19, 
Our species are separated as follows : 
Hind angles of thorax rectangular. 
Anterior margin of thorax with thickened edge. Humeri distinctly 
GEMtiOrm yn nee eee MS SL 2 ee neercyeni eravicaystereee paralellopipedum. 
Anterior margin not thickened but with two approximated dentiform 
elevations. Enimenignomcdentiform es +r een ciara longum. 
Hind angles of thorax obtuse. 
Prosternum in front nearly smooth. 
The two median lines of thorax nearly obliterated. .....tuberculatum. 
Prosternum in front scabrous or punctate. 
The two median lines of thorax rather deeply impressed..ferrugineum. 
A. parallelopipedum Say, (Colydium) Journ. Acad. v, p. 263 ; 
aequicolle Lec. Proc. Acad. 1859, p. 81. 
Piceous, moderately shining, legs and antenne rufous, form oblong- 
elongate. Head moderately punctate, vertex obsoletely bituberculate. 
Thorax quadrate, apex slightly narrower and emarginate, base truncate, 
hind angles rectangular, sides very feebly arcuate from apex to base, disc 
with a sub-marginal impressed line limited externally by an elevation, 
another similar more internal, two feebly impressed sinuous lines at mid- 
dle, between which and the adjacent carina the surface is elevated in an 
oblong tubercle near the apex; apical margin thickened ; surface finely 
punctate. Elytra slightly wider than the thorax, humeri evidently denti- 
form, surface with rows of moderately fine closely placed punctures which 
become smaller toward the tip, intervals very finely punctulate. Body 
beneath moderately densely punctured. Prothorax more coarsely and 
densely. Length .18-.24 inch ; 4.5-6 mm. 
This species is so well known that it will serve as a point 
of comparison for our other species. In the 2 the tubercle 
near the apex is very feeble or absent. 
Widely distributed over the United States, one having been 
taken in California. 
A. lomgumn Lec. Proc. Acad. 1866, p. 378. 
tufo-piceous, moderately shining, more elongate and convex than the 
preceding. Head similar. Thorax longer than wide, sides parallel, slightly 
narrowed near the apex, sculptured similarly to parallelopipedum but with 
two central striz nearly obliterated, the tubercles near the apex more ele- 
vated, the anterior margin not thickened, in the < with two approximated 
dentiform elevations, 2 simple. Elytra not wider than the thorax, humeri 
not dentiform, surface with faint traces of rows of punctures near the base, 
intervals very finely punctalate. Body beneath rather sparsely punctulate, 
under side of head and sides of prothorax more coarsely punctured. Length 
.18—.22 ineh ; 4.5—5.5 mm. 
Occurs in Northern Arizona, Colorado and Oregon. 
