FAMILY EMYSAURID^. 27 



ORDER 11. SAURIA. 



Body long, cylindrical, covered with scales varying in size, or with small scaly granulations . 

 Extremities four. Tail usually very long, thick at the base. Mouth not- capable of dila- 

 tation, armed with teeth. Oviparous. Carnivorous. 



This order comprises about three hundred species, but as they are for the most part inha- 

 bitants of the torrid zone, we have but twelve living and four fossil species in the United 

 States. The State of New- York has but two living representatives of this order. 



(EXTRA-LIMITAL ) 



FAMILY EMYSAURID^. 



Body lizard-shaped, large. Body furnished with large bony plates, often carinated, and forming two 

 elevated crests on the tail. Sides of the body with small scales ; beneath square, slender, smooth. 

 Feet palmate. Head large, often elongated. Fluviatile. Carnivorous. , 



This family corresponds with the order Loricata of Merrem and Fitzinger, and Emydosaurus 

 of Blainville. It appears to be a link connecting; the Chelonida with the order Sauria : it con- 

 tains many extinct species. 



Genus Alligator, Cuvier. Nostrils separated by a bony partition ; forehead divided by a short pro- 

 minent carina. Four large tubercles on the neck, arranged in rows on each side of the vertebral 

 line. Muzzle elongated, broad and obtuse. Teeth unequal. Feet semipalmated, and without 

 indentation. 



A. mississippiensis. (Am. Tr. N. S. Vol. 2, p. 216. Holbrook, Vol. 2, pi. 7.) Dark ash brown 

 above ; lighter beneath. Four carinate plates on the neck, disposed in a square. 



Genus Crocodilus, Cuvier. Muzzle oblong, depressed. Teeth unequal; the fourth passing into 

 grooves, and not into notches, in the upper jaw. Feet palmated. 



We have no Uving representative of this genus in the United States. Dr. Harlan has described 

 and figured, in the Journal of the Academy of Natural Sciences, Vol. 4, p. 15, pi. 1, a fossil species 

 from the greensand of New-Jersey. 

 C. macro rhyncus. Jaw excessively thick. Teeth thick, short and bhmt. 



Genus Gavialis, Cuvier. Head produced into an elongated snout. Teeth subequal, the fourth passing 

 into grooves, and not into holes, in the upper jaw. Hind feet palmated to the end of the toe, and 

 indented at the external edge. Two large holes in the cranium behind the eyes, which may be 

 perceived through the skin. 



This group has no living representative in the United States. I have described, in the Annals of 

 the Lyceum, Vol. 3, a portion of a fossil species from New-Jersey. 



