CLASS REPTILIA.- 



B. Shields Imbricate. 



4. Imbricated Turtle. Chelonia Imbricata, Schw. Testudo, 



Schoepf. t. 18, a. 



Shell elliptically keeled ; shields yellow, spotted and rayed. 

 In the young, the ends of the shields are obliquely truncated, 

 and scarcely imbricate, Caretta Nasicornis, Merrem. Schoepf. 

 t. 17, f. 1. Indian and Atlantic Ocean. 



Ord. 3. Emydosauki. 

 Vertebrae of the back and the ribs free, mobile ; the mouth 

 toothed ; the feet digitate, webbed ; above and beneath co- 

 vered with imbeded squarish plates, with small scales on the 

 sides. 



Gen. 1. Crocodilus. 



Toes 4, 5, claws 3, 3 ; tail compressed, above keeled, ser- 

 rated ; teeth conical in a single series ; tongue fleshy. 

 1. The head depressed; the canine teeth of the lower jaw 

 received 171 a pit in the upper jaw. Alligator. 

 * Feet digitate. South America. 

 Spectacled Alligator. Croc. (Alligator) Sclerops, Schw. 



Seba, 1, t. 104, f. 10, Spix. Braz. 

 With a cross rib between the orbits ; nape with a band of 

 shields. South America and Brazils. The frontal cross 

 rib varies in shape. 



Eye-browed Alligator. Croc. {Alligator) Palpebrosus, Cuv. 

 Eyelids bony ; nape with a band of shields, each bearing a 

 crest. Var. the nuchal shields are sometimes irregular. Croc. 

 Trigonatus, Seba, 1, t. 108, f. 3. Guiana. 



+ Feet, subpalmated. North America. 



Pike-mumzled Alligator. Cayman Croc. (Alligator) Lucius. 



Cuv. Croc. Cuvieri, Leach Zool. Misc. t. 



Head depressed, parabolic, nuchal shields 4. North America. 



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