SIWALIK AND NARBADA CHELONIA. 
13—167 
The production of the gular far in advance of the postgular portion is, however, a 
character of the last-named sjDecies. The length of the upper thickened portion to 
the commencement of the bifurcation is 6-3 inches ; the vertical thickness posteriorly 
being 4*2 inches. 
Distinctness and affinities . — The specimen indicates beyond reasonable doubt the 
specific distinctness of the form to which it belonged both from C. atlas'- (of which 
no specimens occur in the region whence the fossil was obtained) and the species to 
which the specimen represented in pi. XVIII. fig. 4. pertained. The present form is 
very considerably larger than any of the recent gigantic land-tortoises, none of which 
have an epiplastron presenting any close resemblance to the specimen under considera- 
tion. The writer has been unable to identify the latter with any described species of 
Testiido, and as in his opinion it affords good evidence of a very distinct species of 
gigantic land-tortoise, he considers that it indicates a new species, but for reasons 
mentioned below it is considered inadvisable to give it a specific name. Until the 
union or non-union of the pygal plates be known it cannot be determined how close 
is its affinity with G. atlas and M. emys, but the approach made in the structure of 
the epiplastron to that .of both those forms indicates the probability of the three 
belonging to an allied group. 
Cautleya annuligee, Theobald.^ — In the passage cited Mr. Theobald has described 
and figured a free marginal scute of a large tortoise from the Siwaliks of Nila, in 
the Rawal-Pindi district of the Punjab, under the name of Cautleya annuliger. The 
specimen appears to be the last marginal of the right side (the one in contact with 
the pygal scute), and it agrees exactly in form with the corresponding scute of 
Testudo groica. The peculiarity of this specimen consists in the circumstance that its 
union with the last costal and vertebral scutes is a cartilaginous one® ; from which 
Mr. Theobald is inclined to infer that the union of the whole of the marginal series 
of scutes with the costals was a cartilaginous one, and further that the species was a 
purely aquatic emydine. The evidence at our disposal only shows the cartilaginous 
union of the hinder free marginals, and as the specimen indicates an animal agreeing 
exactly in size with the epiplastron described above, and as there is no evidence of the 
existence of a true emydine of equal dimensions in the Siwaliks, it appears highly 
probable that the specimen belongs to the present form. If that be the case the 
specific name of this form will be annuliger ; and since the peculiar union of the hinder 
marginals probably indicates generic distinctness the name Cautleya may also be 
retained ; although the inexpedience of forming a species, and still less a genus, 
upon a specimen like the present has been already noticed in the Introduction, 
where it was shown that unless all the species of large Siwalik tortoises are founded 
upon homologous parts of the carapace there is practically no limit to the number of 
so-called species that may be based upon the remains of a few forms. 
1 The great difEerence in the form of the specimens lends no countenance to the idea that the present specimen may 
belong to a young individual of C. atlas. 
2 ‘ Eec. Geol. Surv. Ind.,” vol. XII. p. 186, and plate (1879). 
8 This surface is the one above a in figure 1 of Mr. Theobald’s plate, which shows the concave outer surface of the bone. 
D 
