174—20 INDIAN TERTIAEY AND POST-TERTIARY VERTEBRATA. 
but is crushed in along the middle line ; the anterior extremity is represented in 
fig, 2b. A malformation exists in the hinder part of the carapace, the 4th vertebral 
and the 3rd costal plates having apparently been double. The sutures between the 
bony scutes are invisible, from which it may be inferred that the specimen is adult. 
The carapace and plastron are united by bony sutures, from which circumstance, 
together with the general resemblance in the form of the vertebral plates to those of the 
two last species, the specimen may be referred to the present genus. The distinctive 
characters of the shell may be best exhibited by comparing it with that of C. sivalensis. 
In the first place the whole shell is still more depressed, and the vertebral region of 
the carapace flatter. The marginal plates, and more especially those of the anterior 
border, are remarkably narrow in an antero-posterior direction, instead of being 
relatively wide: thus the transverse diameter of the 1st marginal of the present 
specimen is D2 inches, and the antero-posterior 0'45 ; the corresponding dimensions 
in C. sivalensis being D2x0'94. The 1st vertebral is pentagonal, considerably wider 
in front than behind, with the lateral borders sinuated : at the junction of the two 
anterior borders an acute process is given off, whicli separates the 1st marginals of the 
two sides, there being no nuchal plate : the antero-external angles of the 1st vertebral 
are much produced and extend as far as the 1st marginal sutures, instead of. being 
placed considerably nearer the median line as in C. sivalensis and G. crassicollis} 
The 1st vertebral is much wider than in C. sivalensis ^ and its very different form may 
be seen by a comparison of the two figures. The 2nd and 3rd vertebral and the 
costal plates are so similar to those of C. sivalensis and C. crassicollis that they afford 
no distinctive characters. On the ventral aspect the anterior extremity of the 
plastron is slightly narrower, and the gular plates perhaps rather shorter. The 
extreme width of the specimen is 5 ’2, and the height of the carapace 1*5 inches. 
There is not the faintest trace of a vertebral keel, but there are indications of the 
existence of costal keels at an earlier age, although they are now practically 
obliterated. There are no traces of areolse. 
Distinctness and aMnities. — The differences pointed out above indicate the specific 
distinctness of this form from C. sivalensis ; and its distinctness from G. hydaspica is 
so evident as not to require special notice. It differs from C. crassicollis still more 
widely than is the case with G. sivalensis. As the only existing form closely allied 
to G. crassicollis mentioned by Gray^ is Glemmys nuclialis (Blyth), from Java, which 
is apparently distinguished from C. crassicollis merely by difference in colouration, 
the form under consideration may be pretty certainly regarded as belonging to a 
new species, which it is proposed to term C. tJieobaldi^ in honour of the collector of 
the type specimen of this and the allied Siwalik species. 
Glemmys theohaldi appears to be a highly specialized form belonging to the G. 
crassicollis group which has entirely disappeared at the present day. 
1 In one specimen in the British Museum (No. 47. 1. 13. 11 ) the antero-external angles of the 1st vertebral plate reach 
to within a short distance of the 1st marginal sutures. 
^ “ Supplement to Catalogue of Shield-Reptiles,” pt. I. p. 41. - 
