1853.] 407 



hairs, more numerous on the head and cheeks; dark plumbeous on the sides and 

 belly, the hairs of the first tipt with brown, of the other with grey and light 

 brown. Head very moderately blunt ; lips white ; ears small, rounded, hairy 

 both within and without, and concealed under the fur ; antitragus large, semicir- 

 cular. Feet dusky, covered with short hair ; thumb with a compressed, rounded 

 nail. Tail above black, beneath dusky, very slightly covered with hair. 



Length 5-2' ; head 1.1. ; ears '125 ; fore leg '9 ; hind leg 1-4 ; tail 1*4. 



Said by Bachman to be the Arv. pinetorum, to which it bears very little re- 

 semblance. 



6. Arvicola nasutus. Capite satis magno, magis quam in caeteris producto. 

 Auribus ovalibus extra pilos exstantibus. Cauda bene vestita, supra fusca, 

 subtus cinerascente. 



Hab. Cum priore. A. nasuta Bach., Journ. Acad. Nat. Sci., vol. viii. p. 296. 

 A. nasutus Wiegman, Arch, for 1843, part 2 p. 53. A. noveboracensis Rich., 

 1. c. p. 84. A. palustris Harlan, Fauna Americana, p. 136; Schinz. 1. c. p. 

 251. 



Hair dark plurubeous, above about equally tipt with dark and light brown, 

 having somewhat of a hirsute appearance, of a uniform mixed color over all the 

 upper parts, beneath dark cinereous tipt with grey. Head moderately large, 

 more elongated than in others. Ears oval, projecting beyond the fur, hairy both 

 within and without; antitragus moderate, semicircular. Feet covered with 

 shining, pale brow^n hair ; thumb tubercle, with a compressed, curved, blunt 

 nail. Tail well covered wnth hair, above dark brown, beneath greyish. 



Length 6-5 ; head 1-8 ; ears '35 ; fore leg -8 ; hind leg 14 ; tail 1-2. 



I have not, myself, met with this species any where but in Pennsylvania, but 

 I have heard of it in almost all the Northern States. It has been confounded by 

 Richardson with the A. noveboracensis of Rafinesque, which it very much re- 

 sembles, but is easily told by the longer and narrower head, and by a difference 

 in the upper incisors. Dr. Harlan, in his Fauna Americana, wishing to deprive 

 Mr. Ord of the merit of having first described the A. riparius, published this 

 species under the name of A. palustris, and quoted A. riparius as a synonym. 

 His own ignorance defeated him in this project, and made his ill faith more ap- 

 parent. Had he only been honest, he would have consulted Mr. Ord on the 

 identity of the two animals, and then might have justly claimed this species as 

 his own. 



7. Arvicola Pennsylvaxicus. Capite satis magno et obtuso, dentibus primo- 

 ribus superioribus marijine interiore le\ iter subsulcatis. Auribus brevibus sub- 

 pilis occultis, antitrago magno, auris aperturam omnino occludente. 



Hdb. In prov'iiiciis borealibus. (Phila., Mr. Ord.) Arv. pennsylvanicus Ord. 

 A. riparius Rich., 1. c. p. 120. A. xanthognathus Dekay, 1. c. p. 90. Lem- 

 mus noveboracensis Raf. A. pennsylvanicus Wagner, 1. c p. 589 ; Schinz., 1. 

 c. p. 247. 



Hair long, soft and glossy, dark lead color, above tipt with brown intermixed 

 with longer black hairs, beneath tipt with shining grey. Head moderately blunt 

 and large, upper incisors very slightly sulcate on the inner edge ; lips white ; 

 ears oval, projecting a little beyond the fur, hairy both within and without ; an- 

 titragus large, semicircular, entirely closing the auditory passage; feet dark 

 brown, covered with short shining hair; thumb tubercle with a short, com- 

 pressed, blunt nail. Tail depressed, well covered with hair, black, beneath a litile 

 paler. 



Length 7 in. ; head 1*4 ; ears -25 ; fore leg -9 ; hind leg 1*7 ; tail 1-8. 

 The dentition is nearly the same as of the A. riparius. In the upper jaw the 

 posterior interior angle is furnished with a small, sharp, posterior lobe, and the 

 third nnolar of the lower jaw terminates in a roundish piece, which is so cut by 

 the last re-entering angle on its inner side as to form another interior salient 

 angle, whence the interior line of teeth in the lower jaw is composed of 12 salient 

 and 11 re-entering angles. 



This species, first described by Mr. Ord, is probably the one confounded by 



