CuAP. III. GENERA AND SPECIES OF CHELONIOIDiE. 385 



through tlie khiduoss of Mr. I. W. P. Lewis. It is found everyAvhere in the 

 Gulf of Mexico and among the "West India Islands, from the Bahamas to Trin- 

 idad, and further south along the coast of Guiana and Brazil. The many speci- 

 mens I have examined leave no doubt in my mind that there exists only one 

 species of this genus in America. But the question now arises, whether the 

 Caouana of the Mediterranean is identical witli that of America. Unlike Sphar- 

 gi.s, the Caouana is common in Europe ; it breeds there as well as in America, 

 and unquestionably is at home in the Mediterranean. It would, therefore, be 

 highly important to ascertain whether the American Caouana ever crosses the 

 Atlantic. This is the more desirable, as Valenciennes has described the European 

 Caouana as a distinct species, under the name of Chelonia Pelasgorum.^ The 

 more extensive range of this species northward along the coast of the United 

 States, might explain its frequence in the Mediterranean, if the Chelonia Pelas- 

 gorum is not a different species. If it is distinct, the American species may yet, 

 as do some of the American Birds, occasionally appear in the Mediterranean, and 

 have been confounded with the European species. There are here four po.ssibil- 

 ities, which render renewed investigations and direct comparisons of European and 

 American specimens very desirable. Either the European Caouana has come from 

 America, following the Gulf Stream, in larger numbers than Sphargis does, and, 

 settling in Euro^je, has become as numerous there as it is on the other side 

 of the Atlantic, the reverse course being impossible on account of the direc- 

 tion of the Atlantic currents ; or, this species, though identical in Europe and 

 in America, has originated separately in both hemispheres ; or, a closer compari- 

 son may show that the European and the American are distinct species ; or, 

 finally, though the European and the American were distinct species, the Ameri- 

 can may, nevertheless, occasionally visit the shores of Eui'ope, as Sphargis does. 

 There are other reasons which render a direct comparison of the Turtles of this 

 genus from different oceans very desirable. Tomminck and Schlegel state,^ that the 

 Chelonia olivacea is the same species as the Caouana, which may wander as far 

 as New Holland and Japan. Such an ubiquitous occurrence of this species can 

 hardly be admitted without more stringent evidence than that alluded to by 

 them, especially when such a mode of distribution runs directly against the well- 

 known direction of the oceanic currents. 



Audulwn stiites, that the Loggerhead, Caouana, feeds mostly on large conchshells. 

 The young of this species, about which more may be found in the following 

 section, are figured in PI. G, fig. 13 to 32, and the eggs, which are more fully 

 described in the Third Part of this work, are repi*esented in PI. 7, fig. 30. 



' Expedition scientifique de la Morde, Paris, 1840, fol. '•' Fauna japonica, Chelonii, p. 2G. 



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