270 THE GALAPAGOS TORTOISES. 



and comparisons; they are too abstract and vary too much with age and sex 

 to be really practicable. 



Excepting in the synonymy and the direct references the bibliography is 

 not repeated; it has been worked out by Gunther, Baur, and Van Denburgh. 



Testudo tabulata Walbaum. 



Plate 2. 



Testudo tabulata Walbaum, 1782, Chelonographia, p. 122; Schoepff, 1792, Hist. Test., p. 56, 62, pi. 12, 

 fig. 2, pi. 13, 14; Dattdin, 1805, Hist, rept., 2, p. 242; Wied., 1825, Beitr., 1, p. 51; Abbild., pi. — ; 

 Bell, 1835, Monogr. Test., pi. — ; Dumeril et Bibron, 1835, Erpetol. gener., 2, p. 89; Gray, 

 1844, Cat. tort., p. 5; 1855, Cat. shield rept., p. 5; Strauch, 1862, Chelon. stud., p. 80; 1865, 

 Verth. schildkr., p. 25; Gray, 1870, Suppl. cat. shield rept., p. 4; Boulenger, 1889, Cat. Chelon., 

 p. 157; Strauch, 1890, Bemerk. schildkr., p. 12; Goeldi, 1904, Chelonios do Brazil, p. 14. 



Testudo denticulata Schoepff, 1792, Hist. Test., p. 119, pi. 28, fig. 1. 



Testudo tessellata Schneider, 1792, Schr. Berl. naturf . freunde, 10, p. 262. 



Chersine tessellata Merrem, 1820, Tent., p. 31. 



Testudo hercules Spix, 1824, Test. Bras., p. 20, pi. 14. 



Testudo sculpta Spix, 1824, Test, Bras., p. 21, pi. 15. 



Testudo carbonaria Spix, 1824, Test. Bras., p. 22, pi. 16; Bell, 1835, Monog. Test., pi. — ; Dumeril et 

 Bibron, 1835, Erpetol. g6ne>., 2, p. 99; Strauch, 1862, Chelon. stud., p. 80; 1865, Verth. schildkr., 

 p. 27. 



Testudo cagado Spix, 1824, Test. Bras., p. 23, pi. 17. 



Chersine tabulata Gravenhorst, 1829, Del. Mus. Vrat. Rept., p. 19. 



Testudo boiei Wagler, 1829, Icon. Amph., pi. 13. 



Chelonoides tabulata Gray, 1873, Proc. Zool. soc. London, p. 724, pi. 60, fig. 3. 



The conclusion reached in this study of the Galapagos tortoises is that they 

 were derived in comparatively recent time, much later than the Tertiary, from 

 species of the nearer lands of the continent of South America. How their 

 transportation was effected may not be determined at present. In order that 

 the closeness of the relationships with one of the most widely distributed con- 

 tinental species may be made the more evident the following description and 

 illustrations of a specimen of Testudo tabulata from Porto Rico are introduced 

 here. They are taken from a fair representative of the species and will be 

 useful in comparisons. The measurements in inches of the specimen are:- 



The shape of the carapace of this species is more elongate than that of T. vicina; 

 it has a circumference of forty-one inches and approaches the subcyclindrical 

 in shape. The sides are steep; they are nearly parallel in an upper view; 

 longitudinally the back makes a long, low arch, which does not rise in the middle 

 as in T. nigrita. The front declivity resembles that of the latter. A majority 



