44 PLATYSTEENID^E. 



plastral shields very variable ; suture between gulars and humerals 

 forming a right angle ; axillary and inguinal large. Head mode- 

 rate ; snout short, rather pointed and prominent ; jaws with den- 

 ticulated edge, upper not notched mesially ; alveolar surface of 

 upper jaw with the median ridge nearer the inner than the outer 

 border ; bony choanse between the orbits ; the width of the lower 

 jaw at the symphysis is less than the diameter of the orbit. Fore 

 limbs with large transverse scales. Carapace olive, that of young 

 with some black spots, especially on the posterior edge of the first 

 three vertebrals ; an orange vertebral band and a narrow yellow 

 margin ; carapace more uniform in the adult ; plastron orange or 

 red, with black spots, or brown with a yellowish anterior and lateral 

 border to each shield, in one specimen uniform yellow. Head 

 blackish ; jaws and sides of crown orange ; neck with numerous 

 yellow lines on a blackish ground ; limbs dark olive, spotted with 

 yellow. 



Length of shell up to nearly 9 inches. 



Hah. Ganges and Indus systems. 



Family III. PLATYSTERNID.E. 



Shell covered with epidermal shields. Caudal vertebras mostly 

 opisthocoelous. Neck completely retractile within the shell. 

 Parietal bones widely separated from squamosals ; temporal region 

 completely roofed over. Digits moderately elongate ; phalanges 

 with condyles ; claws four or five. 



A single genus and species, remarkable for its large head and 

 long tail. 



Genus PLATYSTERNUM, 

 Gray, P. Z. S. 1831, p. 106. 



Plastron moderately large, connected with the carapace by liga- 

 ment ; a series of inframarginal shields separates the plastral 

 shields from the marginals. Head very large, covered above with 

 an undivided horny shield; jaws very strong, hooked, without 

 additional alveolar ridges. Digits feebly webbed, all except the 

 outer toe clawed. Tail very long, subcylindrical, compressed at 

 the end, with rings of squarish shields. 



A single species. 



43. Platystenmm megacephalum. 



Platysteraum megacephalum, Gray, P. Z. S. 1831, p. 107 ; id. Ill 

 Ind. Zool. ii, pi. Ixii ; Giinth. Rept. B. I. p. 43 ; Bouleng. Cat. Chel. 

 8fc. p. 46. 



Platysternon peguense, Gray, Suppl. Cat. Sh. Rept. i, p. 70 ; TJieob. 

 Cat. p. 26. 



