EXTINCT MAMMALIA OF NORTH AMERICA. 405 



ISCHYROMYS. 



Ischyromys typns. 



See page 335, PI. XXVI, Figs. 1-6. 

 Leidy: Proc. Ac. Nat. Sc. 1856, 89; 1857, 89. 



Bear Creek, a tributary of the Sheyenne River, and Mauvaises Terres of White 

 River. Miocene. 



CASTORIDjE. 



CASTOR. 

 Castor canadensis. 



Beaver, Hall : Nat. Hist. N. York, Geol. Pt. IV, 1843, 367. 

 Castor fiber, americanus, Wyman : Am. Jour. Sc. 1850, X, 61, Fig. 4. 



Castor canadensis, Leidy: Holmes' Post-pliocene Fossils South Carolina, 1860, III, PI. XXI, 

 Fig. 2. 



Remains have been found in association with those of Mastodon and other extinct 

 animals, or in similar positions. They have been reported from Memphis, Tennes- 

 see ; Ashley River, South Carolina ; from New York and New Jersey. 



Castor tortus. 



See page 341, PI. XXVI, Figs. 21, 22. 

 Castor (Eucastor) tortus, Leidy: Proc. Ac. Nat. Sc. 1858, 23. 



From the sands of the Niobrara River, Nebraska. Pliocene. 



CASTOROIDES. 

 Castoroides ohioensis. 



Foster : Am. Jour. Sc. 1837, XXXI, 80-83, Figs. 15-17 ; Second Rep. Geol. Surv. Ohio, 1838, 80. 

 Hall and Wyman : Boston Jour. Nat. Hist. 1847, V, 385, Pis. XXXVII-XXXIX. Whit- 

 tlesey : Am. Jour. Sc. 1848, V, 215. Wyman : Am. Jour. Sc. 1850, X, 63, Fig. 5. Agassiz : 

 Proc. Am. Assoc. Cincin. 1851, V, 179. LeConte: Proc. Ac. Nat. Sc. 1852, 53. Pictet : 

 Traite de Paleont. 1853, 1, 253. Leidy : Holmes' Post-pliocene Fossils S. Carolina, 1860, 114, 

 PI. XXII, Figs. 5-8 ; Proc. Ac. Nat. Sc. 1857, 97. Bronn : Leth. Geog. 1856, 1046, PI. 

 LIX, Fig. 8. 



Extinct animal of the order Rodentia, Am. Jour. Sc. 1837, 80, Figs. 15, 17. Harlan : Bui. Soc. 

 Geol. de France, 1839, X, 89. 



Castor {Trogontherium?) ohioense, DeKay : Nat. Hist. N. York ; Zool. I, 1842, 75, PI. XIX, Fig. 3. 



An entire skull found near Clyde, Wayne County, New York ; two rami of lower 

 jaws and a radius, near Nashport, Licking County, Ohio ; the ramus of a lower jaw, 

 at Memphis, Tennessee ; two molars, an upper incisor and two petrous bones, near 

 Shawneetown, Illinois; and fragments of teeth on the shore of the Ashley River, 

 South Carolina. 



