14 BULLETIN 19 9, UNITED STATES NATIONAL MUSEUM 



Suborder Carettoidea^ Fitzinger 



Carettoidea Fitzinger, Neue Classification der Reptilien . . ., 1826, p. 5. 

 Families .■ — One. 



Family CHELONIIDAE Gray 



Cheloniadae Gray, Ann. Philos., ser. 2, vol. 10, 1825, p. 212. 

 Genera. — Four. 

 Range. — Tropical oceans, world-wide. 



KEY TO GENERA OF THE FAMH^Y CHELONIIDAE ' 



1. One pair of prefrontal scutes; costal scutes 4; horny cutting edge of lower jaw 



coarsely dentate, that of upper jaw strongly ribbed vertically; bony alveolar 

 ridge of upper jaw with a low but regularly raised auxiliary ridge behind 

 anterior ridge, which is very strong and terminates anteriorly in a tooth at 



posterolateral corner of premaxillary pit Chelonia (p. 17) 



Two pairs of prefrontals; costal scutes 4-9; horny cutting edge of lower jaw 

 smooth or feebly denticulate, that of upper jaw without markedly elevated 

 vertical ribbing on its inner surface; bony alveolar surface of upper jaw 

 smooth or with a single ridge; this ridge not terminating anteriorly in a 

 sharp tooth 2 



2. Costal scutes 4 pairs; dorsal scutes usually conspicuously imbricate; bony 



alveolar surface of upper jaw with a sharp-crested ridge. 



Eretmochelys (p. 16) 



Costal scutes 5 pairs or more; dorsal scutes not conspicuously imbricate; bony 



alveolar surface of upper jaw smooth or with a rounded ridge 3 



3. Four enlarged inframarginal scutes on bridge; dorsal color gray to olive-green; 



maxillaries not in contact, separated by pre vomer Lepidochelys (p. 14) 



Three enlarged inframarginal scutes on bridge; dorsal color brown or reddish 

 brown; maxiUaries in contact between pre vomer and premaxillaries. 



Caretta (p. 15) 



Genus LEPIDOCHELYS Fitzinger 



Lepidochelys Fitzinger, Systema reptilium, fasc. 1, 1843, p. 30. 

 Caouana Gray, Catalogue of the tortoises ... in the British Museum, 1844, p. 

 52 (type, Chelonia olivacea Eschscholtz). 



Genotype. — Chelonia olivacea Eschscholtz. 

 Species. — Two are generally recognized. 

 Range: — Tropical oceans, world-wide. 



KEY TO SPECIES OF LEPIDOCHELYS 



1. Inframarginal scutes without pores; usually 5 pairs of costal scutes; color usually 

 gray; bony alveolar surface of upper jaw with a conspicuous ridge. 



kempii (p. 15) 



Each inframarginal scute usually with a pore at its posterior border; usually 



more than 5 pairs of costal scutes; color olive; bony alveolar surface of upper 



jaw with a low (not conspicuous) ridge olivacea (p. 15) 



' Deraniyagala (Spolia Zeylanica, vol. 24, 1945, p. 98) suggests that this group may be of pleurodirous 

 origin. 

 ' Adapted from Carr, Proc. New England Zool. Club, vol. 21, 1942, pp. 3-5. 



