REPTILES OF THE VICINITY OF NEW YORK CITY 119 



TURTLES. 



Order Chclonia. 



Of the twelve species of turtles, or chelonians, found locally, 

 three are marine wanderers from warmer climes and of rare 

 occurrence. The marine turtles may be immediately recognized 

 by their peculiar paddle-like limbs which are frequently termed 

 "flippers." The use of these members in the progress of a sea 

 turtle through the water has been appropriately compared to 

 the flight of a hawk or an eagle. Of the other species of chelon- 

 ians, one is strictly terrestrial in habits, while eight species are 

 semi-aquatic and frequent the neighborhood of ponds and 

 marshes. 



The upper shell of a turtle is technically known as the "car- 

 apace," the lower shell as the "plastron." These terms have 

 been employed throughout the description of the species with a 

 view of abbreviation. 



Key to the Turtles. 



a. Limbs long and paddle-like (flip- 

 pers) SEA TURTLES. 



aa. Carapace with seven heavy keels, 



running lengthwise. 



Uniform dark brown Leather - back Turtle 



{Dennochelys coriacea). 



ab. Carapace smooth. 



Olive - brown ; head A^erv 



large ; usually two nails on 



each flipper Loggerhead Turtle 



{Thalassochelys car- 

 etta). 

 Olive or brown, marbled with 



yellow; head of moderate 



size; usually one nail on 



each flipper Green Turtle (Chelonia 



mydas) . 



