Horn.} 548 {April 19, 
tulate. Abdomen densely punctulate with coarse punctures intermixed, 
surface moderately pubescent. Length ,26-.40 inch ; 6.5-10 mm. 
The male has a moderately long process on each side of the declivity, 
in the female reduced to a small tuberosity. 
Occurs everywhere east of the Rocky Mountains. 
A. teres, n. sp. 
Brownish piceous, cylindrical elongate, sparsely clothed with moderate- 
ly long semi-erect pubescence. Front with moderately long erect yellow- 
ish hair. Thorax as broad as long, apex truncate without processes, an- 
teriorly roughly punctate, toward the sides serrate, posteriorly substrigose, 
hind angles not evident. Elytra coarsely seriately punctured, declivity 
regularly convex, not margined nor tuberculate. Body beneath sparsely 
punctate and pubescent. Length .18—.22 inch ; 4.5-5.5 mm. 
In the two specimens before me I detect no sexual differences. 
Occurs at Fort Yuma, California. 
DINODERUWS Steph. 
The species of this genus are of cylindrical form, sometimes very slight- 
ly depressed. The thorax is covered with asperities in front in the man- 
ner usual to the genera of this tribe. 
Here again we have a species (brevis) in which the antenne vary from 
the normal number of joints, there being in the one species six and in the 
others five small joints between the second and the club. The second 
joint of the antenne is usually nearly as stout as the first and short, in one 
species, however, (punctatus) this joint is much more elongate than usual 
as are also the third and fourth, this makes the antennee longer and more 
slender; here also the antenne are fimbriate anteriorly. 
The length of the three-jointed club as compared with the funicle ex- 
hibits an amount of variation which indicates the propriety of suppressing 
the name of one or other of the generic names Dinoderus or Rhizopertha. 
The former is retained as it has the greater number of species in our fauna, 
The surface of the body is sparsely clothed with short erect hairs, in 
punctatus alone the pubescence is not erect. 
The declivity of the elytra is normally convex, two species have it flat- 
tened and limited to a varying extent by a ridge (punctatus, truncatus). 
The other variations of structure are more strictly specific. 
In accordance with the relative importance of the characters above given, 
our species may be arranged in the following manner : 
A. Antenne 10-jointed, form elongate cylindrical. 
Declivity of elytra convex, not acutely margined. 
Margin of thorax coarsely serrate. 
Head opaque, rather roughly granulate. ..,..............poreatus. 
Head shining, smooth, granules small, flat............substriatus. 
Margin of thorax feebly serrate. 
Elytral punctures irregularly disposed. Color piceous. 
