766 



EEPTILIA. 



The sternum has the gular transversely truncated, the post-gular considerably 

 broader than the preanal portion of the young female, and the anal notch broad and 

 its margins obtuse. The sternal ridges, which are posteriorly convergent, are marked 

 by an areolar nodosity on the posterior margin of the pectorals and abdominals. In 

 the adult female, the post-gular region is narrower than the preanal, and the axillary 

 and inguinal diameters are nearly equal. In the male, the characters of the young 

 female prevail, and the axillary is broader than the inguinal breadth. The ridge 

 aU but disappears in the adult female, and in the male it is feeble. The gulars 

 are generally shorter than the post-gulars which are always less than the pectorals. 

 The abdommals are the largest of all the sternal shields, and the preanals are 

 invariably larger than the post-gulars, and occasionally as long, or longer, than the 

 pectorals. In young specimens, the anal suture is sometimes not so long as the 

 posterior margin of an anal, while, in the adult, it is longer than the breadth of 

 the anal notch. 



In some individuals the sternum is projected more forwards than in others, 

 being nearly in a Hue with the anterior margin of the carapace, while in others it 

 is much further back. 



The following table gives the measurements of the carapace and sternum 

 in eleven females and three males, the sexes of which were ascertained by dis- 

 section : — 



Measii,rements of living specimens of Batagur thurgi. 



Out of thirty living examples of this species, of all ages and sizes, only three 

 were males, the largest being only 6""l7 in the length of its carapace, whilst the largest 

 female measured as much as 19'07 inches, in a straight line. I cannot say whether 

 the remarkable discrepancy between the sizes of the two sexes indicated in this table 

 is persistent, but this I can state, that the shells of these small males are fully conso- 

 lidated, and that the penis was so enormously developed that it measured one-half of 

 the length of the carapace. The males are distinguished by the more elongately oval 

 character of their shells, which are not so high as those of the female, and by their 

 longer tails, and these thre^ characters serve at once to distinguish them from the 

 opposite sex. The rarity of the male sex is also worthy of note. 



