430 CHELONIA. 



imbricated shields, ridged in the young, even in the adult ; marginal 

 shields twenty-five or twenty-seven in number. Plastron ridged in 

 the young, with six middle pairs of shields and four lateral ones ; 

 several postaxillar shields. Two claws to either flipper. . 



SrN. — Les ChSlonees caouanes, DuM. & Bibr. Erpet. gen. II, 1835, 551. 



Thalassocheli/s, Fitz. in Zool. Ann. Wien. Mus. (1836), 1841, 128; &, Syst. Kept, i, 

 1843, 30.— BoNAP. Amph. Europ. 1839, 12.— Agass. Contr. Nat. Hist. U. S. Amer. 

 I, 1857, 383. 



Caouana, GrRAY, Catal. Tort. Croc. & Amphisb. Brit. Mus. 1844, 52; &, Catal. Shield. 

 Kept. Brit. Mus. 1855, 72. 



Caouanae, Cantor, Catal. Kept. Malay. Pen. 1847, 13. 



Observ. — The head is much larger than in any other genus of C/ie- 

 lonidae, and the apices of the jaws more powerfully hooked and curved 

 towards one another. The middle occipital plate is remarkable for 

 its development ; it seems to be the centre around which most of the 

 others are disposed. 



Dumeril and Bibron were the first to distinguish the Loggerhead 

 Turtle as a subgeneric group, without however giving any particular 

 name to it. A year afterwards Fitzinger coined for it the generical 

 appellation of Thalassoclielys ; and we dare say that, when John 

 Edward Gray, in 1844, proposed to designate it under the name of 

 Caouana, he meant to reinstate that which ought to have been adopted 

 from the very beginning. In that manner the scientific nomenclature 

 would simply have consecrated a vernacular appellation long since in 

 use. 



In the " Catalogue of Shielded Reptiles," Gray claims priority for his 

 genus Caouana over that of Thalassoclielys, referring the reader to 

 the " Annals of Philosophy for 1825," where we have been unable to 

 detect it. 



The species for which the same author proposes the name of Caouana 

 elongata (Catal. Tort. Croc. & Amphisb. Brit. Mus. 1844, 53 ; &, Catal. 

 Shield. Rept. Brit. Mus. 1855, 73), belongs either to Thalassoclielys or 

 to Lepklochelys, but it is too imperfectly known to enable us to decide 

 that question. It appears to be closely allied to Testudo cepedlana 

 (Baud. Hist. nat. Rept. II, 1805, 50. PI. xvii, fig. 1), which, in our 

 judgment, bears stronger affinities to Lepidochelys than to Thalasso- 

 clielys. 



