434 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



on the north american i.aivd tortoises of the qeivvs 



xe:robatb;.s. 



By FREDERICK W. TRUE. 



[Read before the Biological Society of Washington, Dec. 23, 1881.] 



The laud tortoises, to which this paper is intended to direct attention, 

 are those which are found living within the borders of the United States 

 at the present time. The species, three in number, I shall recognize 

 under the names Xerohates pohjphemns (Daudin) Cooper, the Gopher; 

 Xerohates Agassizii Cooper, Agassiz's Tortoise, and Xerohates Berlandieri 

 Agassiz, Berlandier's Tortoise. 



The Gopher, to speak in general terms, inhabits the southeastern and 

 southern parts of the United States, Xerohates Agassizii the south- 

 western portion, and X. herlandieri the extreme southwest and north- 

 eastern Mexico. 



I. TAXONOMY a:n^d descriptio:n of species. 



History of Xerobates polyphemus. — In tracing- the history of 

 the first of these animals, X. polyphemus, we become involved at once 

 in a whirlpool of conflicting opinion and uncertainty. The first allu- 

 sion to it in zoological literature appears to be in Seba's work upon the 

 curiosities of his museum,* where an imperfect figure is given under 

 the name "Testudo terrestris major americana." No mention of it 

 occurs in the tenth edition of Linnceus' Systema Naturae, but in 

 the interval between the publication of this edition and the twelfth 

 the great naturalist seems to have had his attention called to Seba's 

 figure, for in the latter edition he cites it as the last synonym under 

 his Testudo Carolina, f From this fact and the additional one that 

 in the thirteenth edition of the Systema Xaturce, Gmelin, thinking to 

 improve Linn6's somewhat incomplete description of T. Carolina, added 

 certain remarks on the characteristics of the plastron drawn from a 

 study of the animal portrayed in Seba's work,| some naturalists have 

 thought themselves justified in regarding T. (or X.) Carolina as the 

 proper name for our gopher. Thattliis is not a correct view of the case 

 is made evident by the consideration of the first of Linne's references, 

 the onlj' one which occurs in the tenth edition. The citation is from 

 George Edwards' Natural History, published between 1743 and 1751. 



" Seba, Albert. Locupletissimi rerum natnralium thesauri acciirata descriptio et 

 iconibus artiiiciosissimis expressio, per universam pliysices historiam. Amsterdam, 

 1734-1765, i, pi. HO, lig. 1. 



tLinn6, Syst. Nat., 12th ed., 1766, vol. i, p. 353. 



{Gmeliu, Liuu. Syst. Nat., xiil ed., i, pt. 3, 1788, p. 1041. 



