SIWALIK AND NAEBADA CHELONIA. 
31—185 
“ The fossil agree so closely with 'Emys [^Pangshura] tectum in size and general 
form that the resemblance is observed to be very striking at the first glance. It has 
the same high-pitched, roof-shaped carapace, the same tri tubercular keel occupying 
the first three vertebral plates and similarly formed plastron.” 
Thus far Falconer’s description is very accurate ; the extremely high pitch of 
the fossil carapace is, however, a character agreeing more nearly with P. jiaviventris, 
although it is exhibited in some very young shells of P. tectum} The 1st vertebral 
is pentagonal, and as bi'oad behind as in front : it does not agree exactly with the 
corresponding plate of any specimen of P. tectum that the writer has seen (compare 
pi. XXII. figs. 4. 6. 7. 8.); although rather more like that of P. tentoria (fig. 9.); it 
has not the bell-shape chai acterkstic of P. flaviventris (figs. 10. 11). The 2nd vertebral 
has a distinct keel, and is sub-hexagonal, elongated, and widest at a point consider- 
ably behind its centre, where it is joined by the 1st costal suture ; the longest lateral 
border being in advance of the last-named suture ; its length is nearly one-and-a-half 
times that of the 1st vertebral. In all varieties of P. tectum that have come under the 
writer’s notice the widest point of the 2nd vertebral is either in advance of its centre 
(figs. 4. 6. 7.), or on the sapie line (fig. 8.), and tlie longest lateral border either 
behind the junction of the l|t costal suture, or the two lateral borders are of subequal 
length: in no specimen doesithe length of the 2nd vertebral appreciably exceed that 
of the 1st, The 2nd vertebral of the fossil is very like that of P. tectum turned the 
reverse way. Very similar features prevail in the 2nd vertebral of P. tentoria and 
P. flaviventris (figs. 10. 11) to those of P. tectum. In P. smitJii (fig. 5) the 2nd 
vertebral is extremely short, but the 1st costal suture joins it behind its centre, as in 
the fossil. P. sylhetensis is distinguished from the latter by its very short 2nd 
vertebral. The 3rd vertebral of the fossil is shorter than the 2nd, pentagonal, and 
narrowed behind, with a well-marked keel : it is joined by the 2nd costal suture at a 
point far behind its centre, so that the lateral border in advance of this suture is 
longer than the one behind it. In P. tectum precisely the reverse of this arrangement 
occurs, the lateral border of the 3rd vertebral in advance of the 2nd costal suture 
being longer than the one behind that suture : — in some examples (figs. 4. 6.) this 
feature is very strongly marked, but to a less extent in others (figs. 7. 8). P. 
flaviventris (fig. 10) usually agrees very closely in this respect with P. tectum.^ but in 
the specimen represented in fig. 3 and provisionally referred to that species the 
backward flexure of the 2nd costal makes an approach to the present specimen. 
The 3rd vertebral of P. tentoria (fig. 9) makes a nearer approach to the fossil ; 
although the line of junction between, the 2nd and 3rd vertebrals is different. P. 
smitlii (fig. 5), although differing by the flattened form of the 3rd vertebral, agrees 
in the relative position of the 2nd costal suture. 
The greatest width of the fossil is 3 ’2, and its height 1 "9 inches. 
Distinctness and affinities. — In a group like the present whose existing members 
1 A very young shell in the Geological Department of the British Museum from Falconer’s collection exhibits this 
feature. The 1st vertebral is extremely wide anteriorly, and the 2nd hexagonal, thereby agreeing with var. intermedium. 
