TEST U DO AUSTRAL IS. 471 



rounded. Marginal shields twenty-five; nuchal shield very small. 

 Back depressed ; second and third dorsal shields larger than the rest, 

 transversely elongated. Above blackish, maculated with yellowish- 

 brown; beneath, yellowish-brown, maculated with blackish. 



OBSERV. The " Day-book" of the Expedition thus speaks, in refer- 

 ence to the present species: " A small tortoise was brought us 'from 

 the woods' by a native. It seemed to be well known to others, and 

 was called by them ' Nalala.' ' 



The erpetologist of the Expedition supposed it to be a young of the 

 "Galapagos Tortoise," which, he states, was kept in captivity at the 

 Bay of Islands (New Zealand), in the neighborhood of which the spe- 

 cimen has been found. Upon comparing it, however, with the Gala- 

 pagos tortoise, it became very evident that it did not agree with it, 

 either specifically or generically, at least in the restricted sense we 

 now understand genera. 



The anterior feet are compressed, and not plantigrade, a character 

 recently assigned exclusively to the genus Xerobates* The width of 

 the head, across the temples, is another trait which it has in common 

 with the latter genus. The plastron is immovable, and its anterior 

 extremity alone is curved upwards; the posterior extremity being 

 quite horizontal. 



DESCR. The body of the specimen before us is ten inches long, seven 

 inches wide, and three and a half inches deep. 



The head is large and subtriangular, an inch and three-quarters 

 wide across the temples. It is very much depressed ; its upper sur- 

 face being nearly plane. The snout is rather thick, elevated, and 

 abrupt, though anteriorly rounded. The edge of the upper jaw is 

 slightly arched, whilst that of the lower one is horizontal ; both being 

 denticulated, or rather serrated. The alveolar grooves of the upper 

 jaw are continuous anteriorly, whilst those of the lower jaw do not 

 meet at the symphysis of these bones. 



A pair of frontals and a vertex plate are quite large ; the rest of 

 the surface of the head is covered with moderate and polygonal plates. 

 That portion of the jaws not covered by the horny sheath is likewise 



* Contributions to the Natural History of the United States of North America, 1, 1857, 

 446. 



