Gee ye 409 
compressed sharp nail. Tail slightly compressed, rufous, of the same color 
both above and below. — 
The deutition is the same in every respect as in Arv. riparius. 
We are indebted for this pretty animal, as well as for the preceding species, 
to the researches of Mr. Titian Peale, who was one of the Naturalists of the 
United States Exploring Expedition, under the command of Capt. Wilkes. 
11. Arvicota piIneToRUM. Pilis plumbeo-nigris, supra extremitatibus fuscis, 
subtus argenteo-cinereis. Oculis minimis, vix evidentibus. Auribus sub pilis 
occultis. Pedibus brevibus. Cauda brevi, obtusa, pilosa. 
Hab. In Carolina et Georgia in cultis. Vulg. Mole Rat or Ground Mouse. 
Psammomys pinetorum Leconte, Ann. Lye. 2, 133, tab. 2. Arv. pinetorum Aud. 
and Bach. Quadr. N. A., Vol. ii. p. 215. Wagner, I. c. p. 591. Schinz., 1. c. p. 
249. 
Body cylindrical. Hair short, shining, plumbeous black, above tipt with brown, 
beneath with silvery grey. Head large, short and blunt; eyes very small, scarcely 
visible; ears small, roundish, hairy within and without, entirely concealed under 
the fur; antitragus short, flat, semicircular. Legs short, brown, covered with 
short shining hair; thumb tubercle, with a compressed, curved nail; nails of the 
toes long and slender, naked (no hairs projeeting over them as in every other 
species.) Tail very short, blunt and hairy. 
Length 3-8; head 1-1; ears -15; fore leg -7; hind leg -8; tail -7. 
The dentition of this species, and of the following, differs very much from that 
of any others which I have examined. The molars in the upper jaw are precisely 
like those of the common European species; while in the lower jaw they are 
widely different. Upper jaw: the first molar is composed of 5 triangles, 1 an- 
terior, 2 exterior and 2 interior; the second of 4 triangles, i anterior, 2 exterior 
and 1 interior; the impressed spaces on the crowns of the teeth, in the posterior 
interior triangle of the first and second teeth, are rectangularly oblong ; the third 
molar is formed of three triangles, 1 anterior, 1 exterior and 1 interior, and ends 
in a three-sided piece, which is rounded at its apex, and deeply cut into on the 
interior side by the last re-entering angle. ‘The upper line of dentition consists 
externally, of 9 salient and 8 re-entering angles, and internally, of 8 salient and 
7 re-entering angles. In the lower jaw the first tooth begins with a trefile, then 
follow 6 triangles, 2 exterior, 3 interior and 1 posterior ; the second of 5 triangles, 
2 exterior, 2 interior and | posterior ; the third is narrowed anteriorly, and formed 
of 3 triangles, 1 anterior, 1 intermediate and 1 posterior. 
The lower line of teeth consists, externally, of 7 salient and 6 re-entering 
angles, with two emarginations on the external face of the last tooth, internally, 
of 11 salient and 10 re-entering angles. 
Previous to the year 1810, this I:ttle animal, althongh well known in the pine 
region of lower Georgia for its depredations in the cultivated fields of the inhabit- 
ants, had not made its appearance inthe oak Jands. The first one that lever saw 
was at that time brought to me asa great curiosity; since then they have become 
extremely common, and very destructive to sweet potatoes and ground nuts. 
How long they have been known in Sonth Carolina I have no means of ascer- 
talning. 
Its life is wholly subterranean; it is therefore never seen except when aeci- 
dentally or designedly turned up from beneath the surface. 
12. Arvicoua scaLopsoipes. Capite magno et obtuso; auribus parvis margine 
solo exteriore piloso, sub pilis occultis, tarso subpiloso. Supra castaneus subtus 
cinereus. 
Hab. In Pennsylvania. A. scalopsoides Bachm. Journ. Acad. Sci., Phil., vole 
Vill. p. 299. 
Hair shining, plumbeous, above tipt with chesnut slightly mixed with blackish, 
beneath cinereous tipt with grey, the latter color tolerably distinctly separated 
on the sides from the former. Head large and blunt; ears rounded, hairy in- 
wardly on the upper edge only, concealed under the fur; antitragus small, semi- 
sircular; whiskers grey, longer than the head; feet covered with short shining, 
