SIWALIK AND NARBADA CHELONIA. 
43—197 
the allied Cijclanosteus, in which there are no marginal scutes to the carapace, and 
the ossified scutes of tlie plastron are widely different. The Indian forms have been 
referred to two species under the names of E. granosa (iShoepfP.), and E. vittata^ 
Peters ; the latter being distinguished from the former merely by the larger size of 
the azygos entoplastral callosity, which Dr. Gunther is indisposed to consider as a 
specific character. The Pegu form^ has been referred to a distinct species under the 
name of E. scutata, Peters, which differs from E. granosa only by its colouring. In 
his latest work® Mr. Theobald refers the latter species to E. vittata. 
A. Nuchal scute convex anteriorly^ and ossifying from two centres. 
Species 1. Emyda vittata, Peters.^ 
Syn. E. ceylonensis, Gray.® 
History of Siwalik form. — The question whether the living form should be 
' regarded as a distinct species, or merely as a race of E. granosa, has been alluded to 
in the preceding paragraph. The first record of the occurrence of the species in a 
fossil state in India occurs in a memoir by the present writer® published in 1880. 
FalconeP had, however, previously recorded the occurrence of the genus in the 
Siwaliks of Burma. 
Shell. — The specimen on which the foregoing identification was founded was 
, obtained from the Siwalik Hills and was presented to the British Museum by the 
late General Sir W. E. Baker : it comprises the entire shell, with the exception of 
most of the marginal scutes, and also shows some of the limb-bones. The carapace 
is a good deal obscured by closely adhering matrix, and as no characteristic features 
are shown it has not been figured : the plastral aspect of the shell is, however, very 
perfect, and is represented of one-half the natural size in plate XXVI. fig. 1. The 
six paired plastral callosities correspond exactly with those of the two living species ; 
and the azygos median callosity is of the relatively large size characteristic of E. 
vittata.^ The pair of anterior epiplastral callosities form a rather more open angle 
at their posterior junction than is usual in the living form, but this feature is not 
found in the next specimen, and in any case can scarcely be deemed a specific 
character, and as no other differences can be detected between the fossil and the 
living form the former may be referred to E. vittata, apart from the question whether 
the latter be more than a race of E. granosa. The fossil specimen indicates an 
individual with a shell of about 1 0 inches in length ; the living race according to 
Mr. Theobald attaining a length of 13 *5 inches. The sculpture of the fossil agrees 
1 Syn. E. ceylonensis, G:va,y. 2 Theobald, “ Catalogue of Eeptiles of British India,” p. 32. 
3 ‘‘Burma, its People and Productions, etc.,” vol. I. p. 341 (1882). 
4 ‘ MonatsL. k. Ak. preuss. Wiss.’ 1854. p. 216. 5 ‘ Proc. Zool. Soc.’ 1855, p. 201. 
6 ‘ Journ. As. Soc. Beng.’ vol. XLIX. pt. 2. p. 17. 
7 “ Catalogue of Fossil Vertehrata in Mus. As. Soc. Bengal,” pp. 32, 33 (1852). The genus is here mentioned as a sub- 
genus of Trionyx under the name of Cryptopus. 
3 Compare the specimen figured in Gray's “ Catalogue of Shicld-lteptiles,” pt. I. pi. XXIXa. [E. ceylonensis). 
