762 



REPTILIA. 



marginal, whereas in B. petersi (see figure of the type of B. ocellata) the sixth 

 marginal is completely excluded from touching the inguinal, with which the seventh 

 marginal forms a very broad suture, with nearly the anterior half of the outer 

 margin of the inguinal having the eighth marginal forming the suture along 

 its latter half, the eighth marginal being all but excluded from touching the ingui- 

 nal. The under surface of the plastron of B. ocellata is somewhat more concave 

 than in B. petersi. 



The two males which I have observed are full grown, but considerably smaller 

 than the female which was also adult, and the relative proportion between the 

 sexes is given in the following table. The male differs only from the female in its 

 smaller size and slightly less elevated and narrower shell : — 



Total length of carapace in straight line 



„ of plastron „ 



Axillary breadth .... 

 Inguinal „ .... 



Depth of shell .... 



Adult 6 



Adult $ 



Inches. 



Inches. 



4-95 



7-70 



4-10 



6-65 



2-28 



3-50 



2-20 



3-47 



2-33 



3-70 



The head is much more pointed than in B. ocellata, the muzzle is relatively 

 longer, and the portion below the nostrils much more backwardly sloped than in B. 

 ocellata. The skin of the neck is covered with granules, much in the same way as 

 in B. ocellata, and the limbs with small scales, as in Batagurs generally, but B. 

 petersi has three rather large yellow scales, a little above the base of the first toe. 



The coloration of the two species is markedly distinct ; the shell of B. ocellata 

 is brown-olive, with a large dark-brown round spot in the centre of each of the 

 costals, surrounded by a pale areola, with a dark external border ; the centre of 

 each vertebral is also occupied by an elongated dark-brown spot with a pale- 

 areola around it, and each marginal also shows a tendency to form a brown spot 

 like the foregoing. B, petersi, on the upper surface, is blackish, with a pale 

 narrow greenish-yellow line along the margins Qf the vertebrals, and a light 

 yellow line along the margins of the costals, with a bright yellow margin, as in 

 B. thurgi, along the outer edge of the marginals. Each costal is occupied by a 

 narrow pale greenish ring, the centre of which is the dark black of the upper 

 surface of the shell generally; a narrow greenish-yellow line passes outwards 

 through the middle of each marginal, and these marginal lines tend to join with 

 each other above, external to the yellow costal rings, and to form marginal rings, but 

 they are imperfect at the margin, due to the broad yellow border of the marginals. 

 There is also a distinct tendency, in yellow lines given off from the vertebral 

 aspect of the costal rings, to the formation of another series of costo-vertebral 

 rings, but these rings are generally broken and become imperfect as they touch the 

 vertebrals. A yellow line runs through the nuchal and vertebrals almost to the 

 last vertebral, and from the posterior end of each shield, at the ridge, a greenish line 



