480 DESCRIPTION OF A NEW GENUS AND NEW SPECIES 



small piece is fractured from, its inner edge. The inter- 

 maxillary of the left side is destroyed, except at its inferior 

 part, forming the superior portion of the alveole for the tusk. 



The tusks belonging to this jaw are in a tolerable good 

 state of preservation, though not wholly uninjured. The 

 entire length of the right tusk is seventeen inches, five of 

 which are within the socket. The tusks, where they 

 emerge from the socket, are four inches and three-eighths 

 apart, and at this point they are seven inches and a half in 

 circumference. They do not perceptibly decrease until 

 within about four inches of the extremity, whence they 

 taper to the point ; this is worn in a peculiar manner on its 

 inferior and external surfaces, as may be better understood by 

 the excellent accompanying drawings from the masterly 

 pencil of my estimable friend Mr Titian R. Peale, whose 

 skill and judgment as a naturalist are so admirably displayed 

 by his numerous contributions to the Philadelphia Museum. 



Of the lower jaw [Plate XVIII. Fig. 1 .] about two-thirds, 

 in a good state of preservation, have been obtained ; with the 

 exception of part of the condyloid, the whole of the coronoid, 

 and a small part of the posterior alveolar processes, the right 

 ramus of the jaw is complete, and its inferior and lateral out- 

 line from the angle to the apex is uninjured. Superiorly the 

 coronoid process, as just stated, is destroyed as far as the 

 posterior margin of the second molar tooth ; but thence an- 

 teriorly the jaw is also perfect. Twelve inches of the left 

 ramus are preserved, the condyloid, coronoid, and part of the 

 alveolar processes being broken off, a little posterior to the 

 first permanent tooth. The mental foramen for the exit of 

 the labial branch of the lower maxillary nerve is situated on 

 a line with the root of the second deciduous tooth. Between 

 two and three inches in front of this foramen, which is half 

 an inch in diameter, there are three others of smaller size for 

 the passage of vessels, nerves, &c. to the lip and parts adja- 

 cent to the insertion of the inferior tusks. 



The great peculiarity of this jaw, and that which separates 

 this animal from every genus hitherto established, is its elon- 



