1853.) 235 
There are now five species ‘of this genus known to me; they appear to be 
quite limited in their distribution, and are by no means common in the locality 
where they occur. It is very probable that further investigation in the interior 
of the continent will show that the Dorcadide of North America are quite 
numerous, although thus far they exhibit a lamentable uniformity of color, 
which will render the determination of species somewhat difficult, without 
actual comparison of specimens. 
Nosoperma Soler. 
N. porcatum, depressum, sordide fuscum, thorace latitudine non longiore, 
postice angustato, valde inequali, elytris sutura costisque 3 elevatis, intermedia 
utrinque abbreviata, interstitils irregulariter biseriatim punctatis; apice tuber- 
culatis. Long. :57. 
Sacramento, Mr. Rathvon. Bears a strong resemblance to N. obcordatum, 
but is darker colored, the inequalities of the thorax are smaller and more nume- 
rous, and the punctures and elevations of the elytra much more regular; the 
outer and inner coste end about one sixth of the length of the elytra from the 
tip, in moderate dilatations ; the intermediate costa commences about one fifth 
from the base, and ends about one fourth from the tip; near the tip on each 
elytron is a large rough tubercle. The under surface of the body appears black, 
and is more distinctly punctured than in N. obcordatum. 
There are now three species of this genus known to me as inhabiting the 
United States, viz. N.diabolicum Lec. (Ann. Lyc. 5, 130); N. obcor- 
datum Lec. (NV. trequale}, De}. Cat.; Boletophagus obcordatus Kirby, Faun. 
Bor. Am. 236); and N. porcatum Lec., just described. 
Mycrerus Oliv. 
™ M. concolor, fusco-niger, subtiliter cinereo-pubescens, capite thoraceque 
confertissime subtilius punctatis, elytris alutaceis minus dense subtiliter punc- 
tatis, subtus argenteo-pubescens, tibiis tarsisque vix rufescentibus. Long. :3. 
Sta Fe, New Mexico, Mr. Fendler. The antenne are entirely black, and a 
little longer than the head and thorax. The following diagnosis will distinguish 
the previously described North American species : 
M. scaber, fusco-niger, luteo-pubescens, capite thoraceque confertissime 
punctulatis, elytris grosse sat dense punctatis, antennis pedibusque rufo-testa- 
ceis. Long. -15—-23. 
Haldeman, Pr. Acad. Nat. Sc. 1, 303. 
Southern States, abundant; Pennsylvania, rare. The pubescence of the under 
surface is somewhat silvery; the antenne are a little darker externally than 
at base. 
The only other member of this group of insects yet known from our coun- 
try is, Spheriestes virescens Lec. (Agassiz’? Lake Superior, 232.) 
The Committee on Dr. Woodhouse’s description of a new’ species 
of Dipodomys, reported in favor of publication in the Proceedings : 
Description of anew species of Pouched Rat, of the Genus Dipodomys, Gray. 
By S. W. WoopuovseE. 
Diropomys Orpit. 
Charact. Essent.—Light reddish brown above, beneath white; tail short, and 
penecillate at the end. 
Description. A little smaller than the D. Phillipii, Gray; head and tail 
shorter, nose long and pointed, extending some distance beyond the incisors; 
ears somewhat round, the anterior portion almost naked, posteriorly covered 
with short fine hair. 
