126 
Genus Castor Linn. 
Htymology: Latin, Castor—a Beaver. 
Castor, Linn., Syst. Nat., 1, 1776, 178. 
Generic Characters —Feet four-toed ; hind feet palmate, with the second 
toe double-clawed, Tail broad, flat, and scaly. Body stout and heavy, 
most strongly developed posteriorly. Grinding teeth $#}, single rooted, 
dentinal pulp persisting to a late period in life. General form of skull 
sciurine, but lacking post-orbital precesses. 
Represented by a single living species, formerly distributed over most 
of the northern hemisphere. Two well-marked subspecies are recognized : 
var. fiber of the Old World, and the New World form, var. canadensis. 
Fossil remains scarcely distinct from the present species are found in the 
Quarternary deposits of Kurepe and North America. 
CASTOR FIBER Jinn. 
BEAVER. 
"1766. Castor fiber, Linn., Syst. Nat., ed. 12th, 1, 1766, 78.—Forster, Phil. 
Trans., Lxii, 1772, 375.—Erxleben, Syst. Reg. Anim., 1777, 440.— 
Gmelin, Syst. Nat., i, 1788, 124.—Schreber, Saugt., iv, 1792, 623, 
ol. elxvi (skull), pl. clxxv (@animal).—Shaw, Gen. Zodl., ii, 1801, 
30 —-Tiedemann, Zo6l., i, 1808, 481.—Pallas, Zodzgraphia Rosse- 
Asiatica, 1811, 412—Oken, Naturgesch., 111, 2, 1816, 879.—Cu- 
vier, Régne Anim., i, 1817, 186.—- Desmarest, Mamm., 1822, 
277.—Knox, Mem. Wern. Nat. Hist. Soc., iv, 1828, 548 (anato- 
my).—J. Sabine, Franklin’s Joun. to the Polar Sea, 1823, 659.— 
Say, Lone’s Exped. R. Mts., 1, 1823, 464.—Harlan, Fauna Amer., 
1825, 122.—Godman, Am. Nat. Hist., 11, 1826, 21.—Grifith’s Cu- 
vier’s An. King., v. 1827, 207.—Brandt and Ratzeburg, Mediz. 
Zool., i, 1829, 13; pl. 111, iv, iva.—Owen, Proc. Zool. Soc. Lond, 
1830, 19 (anatomy).—Bennett, Gardens and Menag. Zool. Soc., 
Quad., i, 1885, 153.—Doughty, Cab. Nat. Hist., 111, 1839, 598, pl. 
1.—Waterhouse, Charlesworth’s Mag. Nat. Hist., iii, 1839, 598 
(figure of skull).—Schinz, Europ. Faun., 1840, 57.—Keyserling 
and Blasius, Wirbelt. Hurep., 1840, 31..-Emmons, Quad. Mass., 
1840, 51.—Thompson, Hist. Vermont, 1842, 38.—-De Kay, Nat. 
Hist. N. York, i, 1842, 72, pl. xx, fig. 1, pl. viii, figs. a, b—Nils- 
son, Skand. Faun., 1847, 409.—Woodhouse, Sitgreave’s Hxped. 
down the Zuni and Col. Riv., 1853, 47 (New Mexico).—Giebel, 
Siug., 1855, 619.—-Blasius, Naturgesch. Saug. Deutschl., 1857, 
405.— Wilson, Edinb. New Phil. Journ., 2d ser., viii, 1858, 1 (fossil, 
