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. monax. 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 A. 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. monax there 

 is a distinct indentation on the side of the jaw inside, extending to a depth of perhaps half an 

 inch. 



ARCTOMYS MONAX. 



Woodchnck; Ground Hog. 



Mus monax, LINNAEUS, Syst. Nat. (10th ed.) I, 1758, 601. IB. (12th ed.) I, 1766, 81. 



BODDAERT, Elenchus Animalium, I, 1784, 105. 

 Glis monax, ERXLEBEN, Syst. 1777, 361. 

 Arctomys monax, GXELIN, Syst. Nat. I, 1788, 142. 



SHAW, Gen. Zool. II, 1801, 117, (from Pennant.) 

 DESMAREST, Mamm. II, 1822, 328. 

 SABINE, Linn. Trans, XIII, 1822, 582. 

 HARLAN, F. Amer. 1825, 158. 



GRIFFITH'S, Cuvicr, III, 170; plate (from Lawson). IB. V, 1827, 244. 

 RICHARDSON, F. B. Am. I, 1829, 153 ; (from Godman.) 

 GODMAN, Am. N. H. II, 100. 

 DE KAY, N. Y. Zool. I, 1842, 68 ; pi. xxi, f. 4. 

 AUD. & BACH. N. Am. Quad. I, 1849, 17 ; pi. ii. 



KKNNICOTT, Kep. U. S. Pat. Office, Agricultural for 1856, (1857,) 82 ; pi. x. 

 Glis canadensis, ERXLEBIN, Syst. An. 1777, 363. (Quebec Marmot, of Pennant.) 

 Mus empetra, PALLAS, Nov. Spec. Glir. 1778, 74. 



BODDAERT, Elenchus Anim. I, 1784, 105. 



Ardomys empetra, SCHREBER, Saugthiere, IV, 1792, 743 ; pi. ccx. 

 SHAW, Gen. Zool. II, 1801, 119. 

 GMELIN, Syst. Nat. I, 1788, 143. 

 DESMAREST, Mamm. I, 1822, 329. 

 SABINE, Linn. Trans. XIII, 1822, 584. 

 HARLAN, F. Amer. 1825, 159. 

 GRIFFITH'S Cuvier, V, 1827, 245. 

 RICHARDSON, F. B. Amer. I, 1829, 147 ; pi. ix. 

 FISCHER, Synopsis, 1829, 343. 

 GRAY, Knowsley Menagerie, 1846 ; pi. vii. 

 "Martnota quelekana, PENNANT, Syn. 270," (as quoted by Pallas.) 

 Ardomys melanoptu, KUHL, Beitrage, 1820, 64. (Canada.) 



FISCHER, Synopsis, 1829, 343. 

 Arctomys marmota canadensis, KUHL, Bcitriige, 1829, 64. 



FISCHER, Synopsis, 1829, 341. 



