SPHARfiin.K. 



Suborder T. ATHEC^. 



Euereta, part., S(((n)u'u!i, Zoot. Amph. 1854. 



Clit'ldiiii, part., At/cmiz, Contr. ^\ II. U. .V. i. 1857. 



Oiacopndfs, part., Gray, Siqypl. Cat. Sh. Itcpt. i. 1870. 



Atlioca}, VnpOj I'nir. Amer. Assoc. Adv. Sc. xix. 1870, p. 23o; Dollo, 



Ihdl. Mils. Belij. iv. 1886, p. 91. 

 Dermatochelydaj, Seelei/, Q. Journ. Geol. Soc. xxxvi. 1880, p. 41:?. 

 Paradiacostoidea, part., Baur, Zool. Am. 1887, p. 99. 



Vcrtcbrfe and ribs free, separated from a bony cxoskeleton. Skull 

 without descending processes of the parietal bones. 



Earn. 1. SPHARGID^. 



Sphargid.T, Grai/, Ann. Phil. (2) x. 1825. 



Sjihargidaj, Bell, Zool. Joiirn. iii. 1828. 



Oiacopodes, part., irayler, Si/st. Amph. 1830. 



Cheloniadaj, part., Graij, Si/n. liept. 1831. 



Thalassite.'*, part., Dnnieril >.y Bihron., Erp. Gen. ii. 1835. 



Derniatochelyda?, Fitzinijer, Si/sf. Ilcpt. 1843. 



Cheloniadoe, part., Grciij, Cat. Turt. 1844, and SJi. lirpt. i. 1855. 



Spliargidid;ie, Aijassiz, Contr. N. II. U. 8. i. 1857. 



Spliarjiidiiia, Straach, Clielonol. Stud. 1862. 



Sphargididie, Graij, Suppl. Cat. Sh. Bept. i. 1870. 



Exoskoleton consisting of mosaic-like juxtaposed plates. Plastral 

 elements eight ; no entoplastron. Limbs paddle-shaped, clawless, 

 the digits of the fore limb much elongate : phalanges without 

 condyles. 



1. DERMOCHELYS. 



Dermocheivs, Bhinv. Journ. de Phi/s. Ixxxiii. p. 259 (1816), a7id 



Bull. Soc. Philom. 1816, p. 111. 

 Sphargis, Merrem, Tent. p. 19 (1829) ; Fitzmq. N. Class. Bept. p. 5 



(1826) ; Dum. 8,- Bibr. ii. p. 559 (1835) ; Grai/, Cat. Tort. p. 51 



(1844), and Sh. Bept. i. p. 71 (1855), and Sujypl p. 119 (1870). 

 Coriiido, Fleminri, Phil. Zool. ii. p. 271 (1822). 

 Dermatochelys, Waqler, Si/st. Ajnph. p. 133 (1830) ; Straueh, Chelon, 



Stud. p. 58 (1862) ; Gibith. Rep. Brit. Ind. p. 55 (1864). 



Dorsal shield com])letely, ventral shield incompletely, bony in the 

 adult, the former with seven, the latter with five keels. Beak Avith 

 two triangular cusps, between three deep notelies ; no enlarged 

 alveolar surface, the jaws simply sharp-edged. Head covered with 

 small shields. 



Atlantic, Indian, and Pacific Oceans. 



The vertebral column contains eight cervical, ten dorsal, two 

 sacral, and eighteen to twenty caudal vertebra). The neuro-central 

 suture persists on all the vertebrae save the hindermost caudals. 



