20 BULLETIN 19 9, UNITED STATES NATIONAL MUSEUM 



Family CHELYDRIDAE Swainson 



Chelidridae Swainson, Natural history and classification of fishes, amphibians, 

 and reptiles, vol. 2, 1839, p. 116. 



Genera. — Two, one of which (Macrochelys) is restricted to the 

 United States. A supposed New Guinea genus, Devisia, is an errone- 

 ously labeled Chelydra serpentina. 



Range. — North America south to northern South America. 



Genus CHELYDRA Schweigger 



Chelydra Schweigger, Konigsberg. Arch. Naturw. Math., vol. 1, 1812, p. 292. 

 Chelonura Fleming, Philosophy of zoology , . ., vol. 2, 1870, p. 64 (type, Testudo 



serpentina Linnaeus) . 

 Rapara Gray, Ann. Philos., ser. 2, vol. 10, 1825, p. 211 (type as above). 

 Saurochelys Latreille, Families naturelles du rfegne animal . . ., 1825, p. 92 



(type as above). 

 Cheliurus Rafinesque, Atlantic Journ., 1832, p. 64 (type as above). 

 Emysaurus Dum^kil and Bibron, Erp^tologie g^n^rale, vol. 2, 1835, p. 548 (type 



as above). 

 Chelonura Holbrook, North American herpetology, vol. 1, 1836, p. 139 (type 



as above). 



Genotype. — Testudo serpentina Linnaeus. 



Range. — Southeastern Canada, United States east of the Rocky 

 Mountains, south to Ecuador. 



Species. — Three species or subspecies ; one is definitely recorded from 

 Mexico, another probably occurs there, and the third (acutirostris) is 

 restricted to Panama and South America. 



KEY TO MEXICAN SPECIES OF CHELYDRA 



1. Bridge about one-seventh length of plastron; 4 chin barbels; second vertebral 

 shield 32 to 34 percent length of carapace; height of skull at quadrate 44 to 

 48 percent length of skull to condyle; width of palatine bone 28 to 30 percent 



length of skull rossignonii (p. 20) 



Bridge about one-ninth length of plastron; 2 chin barbels; second vertebral 

 shield less than 30 percent length of carapace; height of skull at quadrate 

 38 to 43 percent length of skull to condyle; width of palatine bone 19 to 

 25 percent length of skull .serpentina (p. 21) 



CHELYDRA ROSSIGNONII (Bocourt) 



Emysaurus rossignonii Bocourt, Ann. Sci. Nat., ser. 5, vol. 10, 1868, pp. 121-122; 



Mission scientifique au Mexique . . ., fitudes sur les reptiles, livr. 1, 1870, 



pp. 18-19, pi. 5, fig. 2. 

 Chelydra rossignonii, Boulenger, Ann. Mag. Nat. Hist., ser. 7, vol. 9, 1902, pp. 



49-51. — Schmidt, Smithsonian Misc. Coll., vol. 106, No. 8, 1946, pp. 1-9. 



Type. — Mus. Hist. Nat. Paris. 



Type locality. — Panzos, Rio Polochic, Guatemala. 



Range. — Atlantic slopes of Guatemala and presumably adjacent 

 Mexico southward to Costa Rica. Not yet reported definitely from 

 Mexico. 



