240 VERTEBRATE ANIMALS OF THE UNITED STATES 



Key to the Genera of Testudinidae 



ai Digits spreading, not closely bound together. 



bi Plastron without hinge, immovably joined to carapace, 

 ci Carapace usually keeled. 



di Size small; mostly under 150 mm. long; keel often 



indistinct or wanting i. Clemmys. 



6.2 Size moderate, carapace over 150 mm. long. 



Ci Salt marsh turtles; along the Atlantic and Gulf 



coasts; plates with growth lines 4. Malademys. 



62 In the central States; plates nearly smooth 5. Graptemys. 



Co Carapace not keeled. 



di Carapace smooth, with rounded margin; size small. 



Ci Carapace with red markings 6. Chrysemys. 



62 Carapace without red markings 8. Deirochelys. 



d2 Carapace with serrated hinder margin 7. Pseudemys. 



b2 Plastron with hinge across the middle, enabling the animal to 

 close its shell. 

 Ci Body depressed; plastron notched behind; upper jaw 



notched in front 2. Emys. 



C2 Body arched; plastron rounded or truncate behind; upper 



jaw hooked in front 3. Terrapene. 



3,2 Digits club-shaped, being closely bound together, only the last 



joint being free; southern States 9. Gopherus. 



I. Clemmys Ritgen. Wood-tortoises. Small turtles with usually 

 a depressed carapace with a more or less prominent keel; plastron joined 

 with the carapace by a wide rigid bridge; feet more or less webbed: 

 4 United States species. 



Key to the Species of Clemmys 



ai In the eastern and central States. 



bi Carapace with small yellow spots on a black background.. . .C. guttata. 



b2 Carapace with deep concentric grooves in each plate and 



serrated behind C. insculpta. 



bs Head with a large yellow or orange spot on each side C. muhlenhergi. 



a2 On the Pacific slope C. marmorata. 



C. guttata (Schneider). Spotted turtle (Fig. 131). Body black 

 above, with numerous small round orange or yellow spots; plastron 

 black, blotched with yellow or orange; carapace smooth, without 

 keel, 100 mm. long and 75 mm, wide: eastern States; southward to 

 northern Florida; westward to southern Michigan; very common. 



C. insculpta (LeConte). Wood-turtle. Shell dark gray or brown 

 in color and much roughened by deep concentric grooves and ridges 

 on each plate; plastron yellow, with a large black blotch on each 

 plate; carapace keeled; length 150 mm.; width 120 mm.; soft parts, 



