78 CHELONIA. 



from which it is at once distinguished by the presence of 

 a thickened ridge on the ventral aspect. 



Cautley Collection. 



40629. The posterior extremity of the plastron. Figured in ' Fal- 



(Fig.) coner's PalaBontological Memoirs,' vol. i. pi. xxx. fig. 2, 



and noticed by the present writer in the ' Palaeontologia 



Indica,' ser. 10, vol. iii. p. 159. The xiphiplastral cornua 



are entire. Presented by Dr. Hugh Falconer, 1845. 



R. 326 r. Part of the right side of the plastron. One of the types. 

 This specimen shows the inguinal notch, and a considerable 

 portion of the hypo- and xiphiplastrals. Prom the con- 

 cavity of the ventral surface it apparently indicates a 

 male individual. 



Transferred from the Indian Museum, 1880. 



Of the following specimens, while some are doubtless referable to the 

 present species, it is probable that others belong to the next form. 



39819. The imperfect cranium. Figured in ' Falconer's Palaeonto- 

 (Fig.) logical Memoirs,' vol. i. pi. xxxi. fig. 1, and also by the 

 present writer in the ' Palaeontologia Indica,' ser. 10, 

 vol. iii. pi. xix. figs. 3, 3 a, 3 b. This specimen would 

 indicate a carapace of about 6 feet in length, and might 

 therefore well belong to the present species. In the 

 extreme excavation of the palate it agrees with the 

 gigantic tortoises of the Aldabra group, and more espe- 

 cially with T. elephantina 1 — the resemblance to the 

 skull of the latter species being especially shown in the 

 emargination of the lateral ridges of the pterygoids, the 

 deep pit between the quadratic condyle and the basi- 

 sphenoid, and the deep depression on the basioccipital. 

 The aperture leading to the auditory labyrinth has more- 

 over the same large size as in the Aldabra tortoises ; and 

 it would seem probable that the opisthotic did not extend 

 beyond the plane of the occipital condyle, as is the case in 

 all those tortoises (fig. 14, B). Cautley Collection. 



R. 956. The 2nd neural bone. This specimen is about one and a 



1 See Griinther, ' Gigantic Laud-Tortoises,' pis. viii., ix. — T. ponderosa is 

 considered by Boulenger (Oat. Chelonians, p. 167) to be identical with T. elc- 



