RODENTIA—SCIURINAE—ARCTOMYS MONAX. 339 
the molars. The deciduous second molar is longer than broad, the reverse being the case in its 
successor ; in other respects they are not very dissimilar. The first two upper molars are not 
replaced until the animal is more than two-thirds grown. 
The preceding description of the characters of the skull of Arctomys is derived chiefly from 
~ undoubted specimens of A. monaz. An immature skull from Wisconsin, (1679,) at first sup- 
posed to be the same, differs in some very essential points, especially, however, in the size of the 
teeth. Compared with a skull of 4. monax, from Essex county, New York, of the same age, 
but a little longer, although the incisors are smaller, the molar teeth are found to be larger in 
every way. Thus the three posterior teeth measure nearly as much as four in the other skull. 
The molars thus extend further forward as well as backward in the Wisconsin specimen. The 
palate between the posterior molars is narrower, but between the anterior ones is of the same 
width. 
It is, perhaps, erroneous to say that Arctomys is without cheek pouches. In A. monawx there 
is a distinct indentation on the side of the jaw inside, extending to a depth of perhaps half an 
inch. 
ARCTOMYS MONAX. 
Woodchuck; Ground Hos. 
Hus monaz, Lannxus, Syst. Nat. (10th ed.) I, 1758, 601.—Iz. (12th ed.) I, 1766, 81. 
Beppaert, Elenchus Animalium, J, 1784, 105. 
Glis monaz, Erxtrsen, Syst. 1777, 361. 
Arclomys monax, Guetin, Syst. Nat. I, 1788, 142. 
Suaw, Gen. Zool. I, 1801, 117, (from Pennant.) 
Desmarest, Mamm. II, 1822, 328. 
Saprne, Linn. Trans. XIII, 1822, 582. 
Haran, F. Amer. 1825, 158. z 
Grirrity’s, Cuvier, II, 170; plate (from Lawson).—In. V, 1827, 244. 
Ricnarpson, F. 5. Am. I, 1829, 153; (from Godman.) 
Gopman, Am. N. H. II, 100. 
Dez Kay, N. Y. Zool. I, 1842, 68; pl. xxi, f. 4. 
Aup. & Bacu. N. Am. Quad. I, 1849, 17; pl. ii. 
Kennicorr, Rep. U. S. Pat. Office, Agricultural for 1856, (1857,) 82; pl. x. 
Glis canadensis, ERXLEBEN, Syst. An. 1777, 363. (Quebec Marmot, of Pennant.) 
Mus empera, Patas, Noy. Spec. Glir. 1778, 74. 
Bopparrt, Elenchus Anim. I, 1784, 105. 
Arctomys empetra, ScuresER, Saugthiere, IV, 1792, 743; pl. ccx. 
Saaw, Gen. Zool. Il, 1801, 119. 
Gmewin, Syst. Nat. I, 1788, 143. 
Desmarest, Mamm. I, 1822, 329. 
Sabine, Linn. Trans. XIII, 1822, 584. 
Haruan, F. Amer. 1825, 159. 
Grirritu’s Cuvier, V, 1827, 245. 
Ricnarpson, F. B. Amer. I, 1829, 147; pl. ix. 
Fiscurn, Synopsis, 1829, 343. 
Gray, Knowsley Menagerie, 1846 ; pl. vii. 
“‘Marmota quebekana, PENNANT, Syn. 270,’’ (as quoted by Pallas.) 
Arctomys melanopus, Kunn, Beitrage, 1820, 64. (Canada.) 
Fiscuer, Synopsis, 1829, 343. 
Ardomys marmota canadensis, Kun, Beitrage, 1829, 64. 
Fiscurr, Synopsis, 1829, 341. 
