70 



Journal op the Mitchell Society [September 



26. Costal plates altering with vertebrals. Western Painted 

 Turtle (Chrysemys cinerea), New York. 



27. Edg-e of one or both jaws serrated. See 28. 



27. Both jaws with smooth edges. Plastron with more or less 

 black. See 32. 



28. Both jaws serrated, with a notch at the symphisis of upper 

 jaw and a strong tooth or cusp on each side of it. See 29. 



28. Lower jaw only serrated, no notch or tooth at tip of up]i(n- 

 jaw. Plastron wholly yellow. See 30. 



29. Carapace red and black, plastron red. (13) Redbellied Ter- 

 rapin (Pseudemys rubriventris). 



29. Carapace as above, plastron yellow and brown. Alabama 

 Terrapin {Pseudemys alahamensis) , Alabama. 



30. Carapace smooth, head very small. Hieroglyphic Terrapin 

 {Pseudemys hieroglyphica), Tennessee. 



30. Carapace with wrinkles on the costal plates. See 31. 



31. Shell comparatively short and high, markings on costal plates 

 mainly transverse. (14) Florida Terrapin {Pseudemys floridunus). 



31. Shell comparatively long and flat, markings on costal plates 

 confused or reticulated. (15) River Terrapin {Pseudemys conciiiiKi). 



31. Shell with an evident keel at all ages. An upright yellow 

 bar behind eye. Black markings of plastron consisting of a roundish 

 black spot on each of the two front plates (sometimes on all or nearly 

 of the plates). (16) Yellow-bellied Terrajun {Pseudemy.'< scripfa). 



32. Shell usually not keeled except in the very 3'oung. Black 

 markings of plastron usually more extensive and elongate. See 33. 



33. An oval red spot behind eye, and conspicuous yellow lines on 

 head, neck and limbs. Red-Necked Terrapin {Pseudemijs elegans), 

 Tennessee. 



33. No red spot behind eye, markings on head neck and limbs 

 obscure or lacking. (17) Troost's Terrapin {Pseudemys troosti). 



34. Shell with concentric striae on the plates. Salt marsh species. 

 See 35. 



35. Keel of each vertebral plate knobbed at tip. Southern Dia- 

 mond-Back Terrapin {Malaclemmys pileata),and subspecies, Florida. 



