42 AMPHITHERIHXE. 



fangs diverge so immediately from the base of the crown, 

 that this presents scarcely any contracted prolongation to 

 which the term ' cervix ' can be properly applied ; the con- 

 trast between the teeth of the Amphitherium, and those of 

 most Saurian Reptiles, is very striking in this respect. The 

 enamelled surface of the teeth of the Amphitherium near 

 the cervix is smooth and polished, and entirely devoid of 

 any close vertical grooves. 



The bifid osseous base which supports the true dental 

 tissues of the teeth of Squall cannot be adduced as a cor- 

 responding structure to the two-fanged lower molars of the 

 Amphitherium, except by a forced and overstrained analogy ; 

 the real bearing of the two-fanged structure of the teeth of 

 the Amphitherium upon the question of its affinities, is kept 

 out of sight by such a comparison ; for it is the implan- 

 tation of the teeth in deep double sockets of a bony jaw 

 by the double fangs which demonstrates the mammalian 

 character of the animal : * the bifid osseous base of the 

 teeth of sharks is attached, as is well known, by ligaments, 

 to a cartilaginous jaw. 



I was well aware, when replying to the objections of M. 

 de Blainville, that portions of the jaws of a gigantic fossil 

 Vertebrate animal, shewing teeth implanted by two fangs, 

 had been discovered in the Alabama tertiary deposits, 

 associated with Corbulee, Modioli, sharks teeth, &c., and 

 that these fossils had been referred by Dr. Harlan to a 

 genus of Saurian Reptiles which he had called Basilo- 

 saurus : but the very fact of the implantation of the teeth 

 by double fangs the first alleged example of such a structure 

 in the Reptilian Class led me to receive the ascription of 



* " The teeth, composed of dense ivory with crowns covered with a thick coat 

 of enamel, are every where distinct from the substance of the jaw, but have two 

 fangs deeply imbedded in it." Geol. Proceedings, Dec. 1838, p. 17. 



