218—10 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
most striking difference is the convexity of the facial profile (pi. XXVIII. fig. 2a), 
caused by the well-marked prominence situated on the nasals half-way between the 
external nares and the orbits ; this character equally distinguislies the specimen from 
C. sivalensis (pi. XXVIII. fig. 3). The expansion at the ninth tooth is decidedly 
greater than in either G. palustris^ or G. sivalensis ; and there is a total absence of 
the preorbital nodose rugosities of G. palusiris, in which respect the fossil comes 
nearer to G. sivalensis. The deep concavity which occurs behind the maxillo- 
premaxillary suture both in G. palustris and G. sivalensis is almost entirely wanting. 
The nasals are relatively wider than in the former species, and thereby agree with 
0. sivalensis. The facial sculpture has the pits more elongated than in C. palustris ; 
but the extremities of the premaxillae are almost smooth, as in that species, and 
thereby differ widely from 0. sivalensis. The premaxillae likewise agree with those 
of the former species in the relative shortness of their facial aspect, the length of 
which is considerably less than that of the narial aperture. The relative position of 
the latter is the same as in C. palustris, but it is of relatively larger size, and its 
posterior half proportionately wider.^ On the palatal aspect (pi. XXVIII. fig. 2) 
the fossil agrees with C. palustris and 0. sivalensis in the relatively wide maxillae and 
premaxillse, and it is probable that it also agreed in the form and position of the 
premaxillary fissure (/?m. /.), of which the boundaries are imperfect; the maxillo- 
premaxillary suture differs, however, from that of the typical form of the former 
species by extending as far back as the seventh alveolus, and also differs from the 
Ceylon variety of that species and from C. sivalensis by its direction, which, instead 
of forming an inverted V, is directed inwards and backwards on the two sides but 
transversely towards the middle of the palate. 
Other specimens. — A much-damaged middle portion of a cranium from Perim 
Island in the Indian Museum (No. E. 185) shows the nasal protuberance characteristic 
of the type specimen. A second specimen^ in the latter collection (No. E. 35) from 
the same locality, comprising the anterior portion both of the cranium and the 
mandible, but in a much-weathered condition, likewise exhibits the characteristic 
convex facial profile. The middle portion of a younger cranium in the Indian 
Museum (No. E. 32) obtained by Mr. W. T. Blanford from Perim Island appears 
to agree in the form of its profile with the type, but the maxillo-premaxillary suture 
does not extend quite so far back. The British Museum possesses two specimens 
from Perim Island which were transferred from the old Indian Museum ; the one 
shows the anterior part of the cranium, and the other that of both cranium and 
mandible, and both exhibit the characteristic nasal prominence, and on the palatal 
aspect the maxillo-premaxillary suture extending backwards as far back as the 
seventh alveolus. 
1 Compare the figures of specimens of all ages given by Gray in the “ Catalogue of Shield- Reptiles,” pt. 2, pp. 10-12. 
2 The borders of the anterior half have been somewhat broken in the specimen. 
3 This is the specimen (No. P. 197) noticed on page 214 of Falconer’s “ Catalogue of Fossil Vertehrata in Museum of 
Asiatic Society of Bengal.” The matrix leaves no doubt as to its place of origin. 
