210 REPTILIA: TESTUDINATA. XXX. 



313. CHRYSEMYS Gray. (xpvv6s, gold; 



616. C. picta (Hermann). PAINTED TURTLE. MUD TURTLE. 

 Greenish black ; plates margined with paler ; marginal plates 

 marked with bright red; plastron yellow, often blotched with 

 brown. L. 8. E. U. S., one of the most common turtles. (Lat., 

 painted.) Westward it gives place to 



617. C. marginata (Agassiz). Plates of carapace alternating 

 or in quincunx, the lateral rows out of line with the middle one, 

 instead of forming sets of three as in the eastern form ; lateral 

 plates with strong concentric strisB. W. N. Y. and W., common. 

 Perhaps a variety of the preceding, but I have seen no inter- 

 gradations. 



618. C. oregonensis Holbrook. No red markings. Minn, to 

 Ore. 



314. CHELOPUS Rafinesque. (x^vs, tortoise ; irovs, foot.) 



a. Carapace usually more or less keeled ; upper jaw deeply notched and arched 



downward. (Chelqpus.) i 



b. Head not notably narrower below than above. 



619. C. muhlenbergi (Schweigger). Brown with yellowish 

 markings ; plastron black with yellowish blotches ; an orange spot 

 on each side of neck ; plates of back plain or concentrically grooved. 

 L. 4J. E. Penn and N. J. 



bb. Head decidedly narrower below than above. 



620. C. insculptus (Le Conte). WOOD TORTOISE. Shell car- 

 inated, its plates marked with concentric striae and radiating black 

 lines ; reddish brown ; plastron with a black blotch on each plate. 

 L. 8. E. U. S., E. of Ohio, in woods and fields. (Lat., engraved.) 

 aa. Carapace not keeled; upper jaw slightly notched, its edge nearly straight. 



(Nanemys Agassiz.) 



621. C. guttatus (Schneider). SPECKLED TORTOISE. Black, 

 with round orange spots, these spots rarely obsolete ; plastron 

 yellow, blotched with black. L. 4J. E. U. S., W. to N. Ind. 

 (Levette), abundant E. (Lat., spotted.) 



315. EMYS Brongniart. (epvs, a mud turtle.) 



622. B. meleagris (Shaw). Black; usually with yellowish 

 spots; plastron yellowish with black blotches; head with yellow 

 spots ; young nearly circular, and black. L. 8. N. Y. to Wis., 

 scarce. (fieXeaypt'y, guinea-fowl.) 



316. CISTUDO Fleming. (Lat., cista, box.) 



623. C. Carolina (L.). COMMON Box TURTLE. Colors very 

 variable, chiefly blackish and yellowish ; no two alike in pattern ; 

 iris red in $ ; hind feet with 4 toes ; young keeled, the keel grow- 



