CHAPTER III 



REPTILES 



A TURTLE 



Many species of land and fresh-water turtles occur in the United 

 States. The following table will aid in identifying some of the 

 common species. The flatter species are much more favorable 

 objects of study than those with a high, convex shell. 1 



A. Turtles with well-ossified shell, covered with horny plates, 

 i. Plastron with 9 to 11 plates. 



Kinosternon subrubrum, the small mud turtle. Shell dark brown; 



head dark, spotted with yellow ; length of carapace 3 or 4 inches ; 



aquatic. 

 Kinosternon odoratum, the musk turtle. Shell dusky brown, often 



spotted or blotched ; head with yellow stripes ; length of carapace 



4 inches; odor of musk; aquatic. 

 Chelydra serpentina, the snapping turtle. Plastron small and cruci- 

 form; length of carapace 1 foot; aquatic. 

 2. Plastron with 1 2 plates. 



Clemmys guttata, the spotted turtle. Carapace black, with small 



yellow spots; length of carapace 4 inches; aquatic. 

 Clemmys insculpta, the wood turtle. Carapace with a keel and with 



its plates marked with concentric ridges; length of carapace 



6 inches; terrestrial and aquatic. 

 Terrapene Carolina, the box turtle. Shell high and very convex; 



plates with concentric ridges; color yellow; plastron with a hinge; 



terrestrial. 

 Chrysemys picta, the Eastern painted turtle. Color greenish-black; 



plates edged with yellow; marginal plates marked with crimson; 



throat striped with yellow ; length of carapace 5 inches ; aquatic ; 



Atlantic states. 

 Chrysemys marginata, the Western painted turtle. Similar to the 



above ; central and Western states. 



1 These descriptions have been modified from Pratt's "Manual of the Verte- 

 brates of the United States." 



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