Carapace variably marked with yellow; dark color on the plastron not 

 confined to the edges of the plates; toes about half webbed; shell oval; 

 Maine to Wis. and Ga. 



Terrapene Carolina (Linn.) Common Box Turtle 



24. Feet club-shaped, not webbed; toes not distinct; claws thick and blunt; 



terrestrial; southern U. S. only Tortoises 25. 



Hind feet somewhat webbed; claws narrow and pointed; either terrestrial 



or aquatic Terrapins 27. 



25. Length of shell less than twice the depth; Texas 



Gopherus herlandieri ( Agassiz) Texas Tortoise 

 (Xerobdtes herlandieri Agassiz) 

 (Testudo herlandieri (Agassiz) ) 

 Length of shell more than twice the depth 26. 



26. Scales of forearm uniform; front area of plastron sloping slightly up- 



wards; Nev. and Utah to Texas and Cal. 



Gopherus agassizii (Cooper) Agassiz's Tortoise 

 Scales of forearm not uniform, some being spiny and larger than others; 

 front area of plastron turning sharply upwards; Fla. to S. C. and Ark. 



Gopherus polyphemus (Daudin) Gopher Tortoise 



27. With a ridge along the grinding surface of the upper jaw parallel with 



the thin, outer cutting edge; usually, but not always, with a ridge 

 along the grinding surface of the lower jaw; plates of carapace usually 

 smooth or with lengthwise furrows or ridges; rarely with a blunt keel 

 along the middle of the carapace in the adult; head and neck con' 

 spicuously colored with light lengthwise stripes and markings, except 

 in a few of the species with a serrated or fluted posterior margin of 

 the carapace 28. 



No ridge along the grinding surface of the jaws; plates of carapace 

 usually smooth or with concentric ridges (not color markings), some 

 times with a few fine lengthwise ridges in forms with a high mid' 

 dorsal keel in the adult; species having the rear margin of the cara' 

 pace serrated have a pronounced keel along the middle of the carapace 

 in the adult; head not definitely striped in forms having the rear border 

 of the carapace smooth 45. 



28. Rear margin of the carapace smooth, except for a sHght notch in the 



middle Chicken and Painted Turtles 29. 



Rear margin of the carapace serrated or fluted Sliders, Cooters 33. 



29. Marginal plates of carapace with yellow markings; with a very broad 



yellow band running down each front leg; head and neck about one' 

 half as long as the shell; N. C. and Fla. to Texas and Okla. 



Deirochelys reticularia (Latreille) Chicken or Long-necked 



Turtle 

 (Chrysemys reticulatus (Bosc) ) 

 Under marginal plates of carapace with red markings; front leg with 

 one or more fine stripes, or else unstriped; head and neck shorter 

 Painted Turtles or Terrapins 30. 



30. Vertebral plates of carapace almost in a line with the costal plates; plas- 



tron usually plain yellow 31. 



435 



