382 AMERICAN TESTUDINATA. Part II. 



extends all over the Gulf of Mexico, and along the coasts of the southern 

 United States. I have seen it alive at Key West (Florida) ; specimens were 

 also brouglit to me from that locality by my young friend, Theodore Lyman, of 

 Boston. It is occasionally seen along the coasts of Mississippi, and all along 

 the coasts of Texas and Mexico. It is frequent around Yucatan, in the Little 

 Antilles, and especially about Jamaica and the Cayman Islands ; it extends also 

 along the coasts of Guiana and Brazil. Whether the specimens observed by 

 Tschudi, on the coast of Peru, belonged to this or the next species, I am unable 

 to state; nor do I know whether it occurs on the Atlantic coast of Africa. 



Eketmochelys squamata, Ag} This species is as common in the Indian and Pacific 

 Oceans as the preceding in tropical America. It has been observed by Siebold 

 on the coasts of Japan; it is already more common in the Chinese waters; it 

 is frequent about the Sunda Islands, New Guinea, and Borneo, and in the Indian 

 Ocean about the Seychelles. Dumeril and Bibron quote it from Isle Bourbon, 

 and Lesson from the low islands of the Pacific. 



Young specimens of Eretmochelys imbricata and squamata are very similar, 

 heartrshaped ; but while Eretmochelys squamata preserves this form to old age, 

 the adult Eretmochelys imbricata is more elliptical. The squamation is also very 

 similar; but Avhile Eretmochelys squamata has distinct, though small horny plates 

 upon the neck, Eretmochelys imbricata has none, and exhibits only minute folds 

 in the skin. The keels upon the large epidermal scales of the shield are much 

 more developed in Eretmochelys squamata than in Eretmochelys imbricata. There 

 is one median ridge upon the scales of the vertebral row from the first scale 

 to the last; in the Atlantic species, only upon the last four scales. There are, 

 besides, converging ridges vqjon all these median scales in Eretmochelys squamata, 

 and only upon the last two in Eretmochelys imbricata. In Eretmochelys squamata 

 the scales of the costal row exhibit prominent ridges, arising from the angles 

 they form with the marginal scales, and extending to the posterior free angle of 

 each scale, of which no trace is observable in Eretmochelys imbricata, neither in 

 young nor in adult specimens. These ridges are intersected by the lines of growth, 

 and have the appearance of a projecting chain. The ridges upon the middle 

 rows of the sternal scales are much more prominent in Eretmochelys squamata 

 than in Eretmochelys imbricata. The projecting ridges of the scales of the mar- 



^ I adopt, as the specific name of this Turtle, one Testudo niacropus, Walb., because it is the oldest 



of the synonyms refen-ed by Linna?iis to the preced- name applied to a Turtle supposed to be identical 



ing species. I select this in preference to several with Eretmochelys imbricata, and also because the 



others, such as Caretta nasicornis, Merr., Chelonia name squamata is particularly appropriate for a spe- 



multiscutata, KnliL, Chelonia Pseudo-Caretta, Les., or cies from which the tortoise-shell is obtained. 



