476 DESCRIPTION OF A FRAGMENT OF 



cate the species to our friend Mr Lea, by the designation 

 Least. 



We hesitate attempting to indicate the generic and spe- 

 cific characters with the imperfect knowledge we possess of 

 all the animals of the order to which it belongs ; and at all 

 events will postpone doing so till we can collect more com- 

 plete remains of our animal. 



Since I had the honour of laying before the society the 

 description of a portion of the head of a new fossil animal 

 from New Jersey, I have had an opportunity of examining 

 the fossil organic remain in the cabinet of the society, pre- 

 sented by Lewis and Clark. I find that this specimen con- 

 sists not only of a portion of a dental bone, but also a small 

 part of a coronoid bone ; and that the teeth, instead of being 

 "in a longitudinal groove" "in close contact throughout," 

 "there being no distinct, separate alveoli," are in fact placed 

 in distinct alveoli. 



The most important generic character which was sup- 

 posed to distinguish this animal from the one we described 

 having thus no existence, it appears proper in the present 

 state of our knowledge to place the two species in the same 

 genus ; and, as the genus Saurocephalus is founded on erro- 

 neous characters, and will not admit our species, it becomes 

 necessary to construct a new genus, which we shall accord- 

 ingly do, and shall retain for it the name Saurodon. 



Genus Saurodon (Hays). Teeth of the lower jaw closing 

 within those of the upper, like incisors ; a regular series of 

 foramina along the inner aspect of the jaws near their alveo- 

 lar margins, for the passage of nerves and blood-vessels to the 

 teeth. 



Species 1. S. laneiforrnis. A groove along the inner 



