246 VERTEBRATE ANIMALS OF THE UNITED STATES 



Subspecies of C. marginala 



C. m. marginata Agassiz. Northern New York to Wisconsin; south- 

 ward to Missouri. 



C. m. belli (Gray) . Yellow margins of dorsal plates absent; plastron 

 with a pair of wide black bands joined at the ends: Great Plains; west- 

 ward to Vancouver Island; northeastward to northern Michigan. 



C. m. dorsalis Agassiz. Carapace with a yellow dorsal stripe: 

 lower Mississippi Valley; northward to Missouri. 



Fig. 136. — Chrysemys picla {from Fowler). 



C. pida (Schneider) (Fig. 136). Similar to C. marginata; plastron 

 yellow; vertebrals nearly in same transverse line as costals: eastern 

 States from New Brunswick to Georgia; very common. 



7. Pseudemys Gray. Sliders; cooters. Carapace moderately de- 

 pressed, with a serrate hinder margin; plastron notched behind; upper 

 jaw notched in front; head covered with a hard skin: 10 species. 



Key to the Species of Pseudemys 



ai Carapace smooth — not wrinkled with parallel grooves P. troosti. 



a,2 Carapace wrinkled, especially along the sides. 

 bi Edges of jaws smooth — not serrate. 



Ci Elongate red patch back of eye P. elegans. 



C2 Broad yellow patch back of eye P. scripta. 



hi Lower jaw serrate. 



Ci Upper jaw smooth P. concinna. 



C2 Upper jaw serrate, at least with central notch and 

 lateral cusp. 



di Plastron red; Atlantic coastal plain P. ruhriventris. 



do Plastron yeUow; Gulf States and lower Mississippi 

 VaUey. 



-.y 



