760 REPTILIA. 



The allantoic bladder is very large, and perhaps more free than in the true 

 Batagurs. It consists of two halves with a narrow isthmus, the left half always the 

 larger. When dilated, it equals in size the whole of the other viscera put together, 

 and its walls are very delicate. The cloacal bladders are small and globose, and 

 covered internally with numerous vilU. There are large glandular structures in the 

 inguinal region. 



The apex of the lung is partially divided in two, and below this it is externally 

 contracted ; the portion below this, again, consists of three lobes one before the 

 other, the terminal, or most inferior, being moderately long and fine, with the 

 kidneys behind and along its inner border. In a male, with the carapace 6 inches 

 long, the lung measm'ed when distended 3*50 inches long, with a breadth at the 

 apex of l"-97. 



The iris is of a pale sparkling metallic yellowish- white, much mottled with black, 

 especially anteriorly and posteriorly, producing in some the appearance as if a black 

 band passed through the iris. 



The axiUary and inguinal septa are but little developed, and the vertebral for- 

 mula in the female is C. 9, D. 8, S. 3, 0. 19, or 20. In some males, there are 

 a fewer number of caudal vertebrae than in the female, although the tail is 

 considerably longer in the former than in the latter sex. But the greater length 

 is brought about as in other species by the much longer and larger vertebrse of the 

 male. The transverse processes in the caudal vertebrse begin to show themselves 

 strongly on the seventh, and increase to the thirteenth, beyond which they diminish, 

 disappearing on the last three. 



By its skuU this genus is closely allied to B. thurgi, having a similarly formed 

 palate and internal nares, the former, however, being less pitted than in H. tJiui'gi. 

 The grooAdng and ridging of the mandible are also the same, or nearly so, as in that 

 species, only the palate has a proportionally greater antero-posterior expansion, and 

 the coronoid process does not rise above the level of the post-coronoid portion of the 

 ramus, being outwardly directed and sessile. The sub-genera, Sardella and Morenia, 

 if there were no other characters but those derived from the skull to separate them, 

 might with propriety be united ; but the different structure of their shells, and the 

 remarkably elongated lung of Sardella, suffice to distinguish them as two sub- 

 generic modifications of Batagur. 



The skull is remarkably distinct from the skull of B. (M.) petersi, Andr., 

 differing from that species in being much broader, and more especially in its having 

 a much shorter and broader muzzle. 



This appears to be one of the most prevalent species in Arracan and Burma. 

 It is thoroughly aquatic in its habits, but has nevertheless the power of living out 

 of water for a lengthened period, doubtless by reason of its large allantoic bladder. 

 It is very gentle in its habits, and does not attempt to bite, but when suddenly 

 handled emits a kind of hissing noise, retracting itself into its shell. It lives on the 

 bulbous roots of aquatic plants like its near congener, Batagur tlmrgi. 



