112 POST-PLEIOCENE .FOSSILS. 



Castor fiber, Say, Harlan, etc. 



Castor fiber, Wyman, Am. Jour. Sci., 2d ser. X, 61. 



Remains of the Beaver are not unfrequently found throughout the United States, in 

 recent, deposits, in localities in which the animal is not now existing. Prof. Wyman has 

 further described remains of the Beaver, found in association with those of Mastodon, 

 Megalonyx, and Castoroides, in the vicinity of Memphis, Tennessee. The cabinet of the 

 Academy of Natural Sciences, of Philadelphia, also contains portions of skulls and jaws 

 with teeth, found together with remains of the Mastodon, in marshes in New- Jersey. 

 Teeth of the Beaver, jet black in color, have likewise been obtained by Prof. Holmes and 

 Capt. Bowman, from the Post-Pleiocene deposit of Ashley river. 



Genus, H Y D R O C H O E R U S. — Brisson. 



HYDEOC II E E US A E S P I . 



Plate XXI. Figs. 3-6. 



Oromys Eesopi, Leidy, Proc. Acad. Nat. Sci., Phila., VI, 241. 

 Hydrochoerus Aesopi, Leidy, Proc. Acad. Nat. Sci., Phila., VIII, 165. 



In 1853 I received from Prof. Holmes a small fragment of an incisor tooth, obtained 

 from the Post-Pleiocene deposit of the Ashley river. The specimen I suspected to 

 indicate a large rodent animal, allied to the South-American Hydrochoerus capijhara, and 

 characterized it under the name of Oromys Aesopi. Capt. Bowman's collection of fossils, 

 from the Ashley river beds, subsequently received, was found to contain portions of two 

 molar teeth, which prove the former specimen really to have belonged to a species of 

 Hydrochoerus. More recently Prof. Holmes obtained an additional fragment of a molar 

 tooth, from the Ashley Post-Pleiocene deposit. 



The fragment of an incisor referred to, belonging to the lower jaw, is a little more than 

 an inch in length, and measures five lines in breadth, but does not differ from the corres- 

 ponding portion of the same tooth in the recent Capybara, except that the enamel is more 

 strongly ridged, longitudinally, than in any of the specimens with which it was compared. 



Of the two portions of molar teeth, of Capt. Bowman's collection, both belong to the left 

 side of the lower jaw. One of them consists of the posterior three enamel folds or columns 

 of the second tooth in the series, and the other consists of the anterior two columns of the 

 last tooth. The former specimen measures four-and-a-half lines transversely and antero- 



