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 Dorcadidae 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. 



NosoDER3iA Solier. 



N. porcatum, depressum, sordide fuscum, thorace latitudine non longiore, 

 postice angustato, valde inaequali, elytris sutura costisque 3 elevatis, intermedia 

 utrinquc abbreviata, interstitiis 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 costae 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. di abo 1 ic u m Lee. (Ann. Lye. 5, 130) ; N. obcor- 

 datum Lee. (iV. inaquale[ Dej. Cat. ; Boletophagns ohcordaUis Kirby, Faun. 

 Bor. Am. 236) ; and N. porcatum Lee, just described. 



Mycterds OHv. 



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 antennae are entirely black, and a 

 little longer than the head and thorax. The following diagnosis will distinguish 

 the previously described North American species : 



M. s caber, 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 antennae are a little darker externally than 

 at base. 



The only other member of this group of insects yet known from our coun- 

 try is, Sphaeriestes virescens Lee. ( 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 a new species of Pouched Rat, of the Genus DipodomyS^ Gray. 



By S. W. WooDHousE. 

 DiPODOMYs Ordii. 



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. 



