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452J AMERICAN TESTUDINATA. Part II. 



4tli. The Ifciicaii Fauna. I have to mention this Fauna on account of its exten- 

 sion into the bovmdaries of the United States. Among its characteristic Testudi- 

 nata found along the Rio Grande, the most remarkable are Xerobates Berlandieri 

 and Aspidonectes Emorji. Platythyra flavescens extends further north, even as far 

 as Arkansas, while Thyrosternum sonoriense occurs further west, in Sonora. The 

 Turtles of Cuba, as far as I know them, differ specifically from those of this and 

 the preceding Fauna. 



5tli. The Callfornian Fauna has a wdde range from north to south, beginning 

 at the straits of Juan de Fuca and extending to the Gulf of California, and yet over 

 this whole extent of country only a single Turtle is found, Actinemys marmorata; 

 for it is not true, that the Galapago Turtle occurs also in California in a wild 

 state ; and the existence of a distinct species of Cinosternum on that side of our 

 continent appears very doubtful to me. (Comp. p. 429.) 



There is a very striking resemblance with what obtains in Europe in this 

 scarcity of Testudinata in California, contrasted with their extraordinary diversity 

 and great number on the eastern side of the continent. This, again, recalls their 

 profusion in eastern Asia; so that, even with reference to the sj^ecial geographical 

 distribution of the Testudinata, the great laws that obtain with regard to the simi- 

 larity and differences of the continents are fully confirmed. 



After what has just been stated, it is hardly necessary to call especial atten- 

 tion to the fact, that, upon a map representing the geographical distribution of 

 the Testudinata in North America, the whole table-land between the Sierra Nevada 

 of California and the Rocky Mountains, as well as the eastern slope of the latter, 

 down to the Great American Desert, would be left entirely blank, not a single 

 species of Turtles extending over any part of this extensive tract of land. It would 

 be a mistake, however, to infer, from this fact, that these animals are excluded from 

 mountainous regions. In the range of the Alleghauies there are many species, which 

 ascend to the height of several thousand feet, and among those that reach the 

 greatest heights are Cistudo virginea, Chelydra serpentina, and a species of Aspido- 

 nectes, probably Asp. nuchalis (comp. p. 406); but I I'egret that I am unable to 

 give the absolute height with any degree of accuracy. 



