TPtlONYX GUNTHERI. 49 



Siani, shell 7 inches long ; one from Ganiboja, which is young, and has been figured by 

 Dr. Gray ; the third specimen, shell 9 inches long, is from Sarawak (Borneo) : the first of 

 them is figured on Plate VI. 



Trio.nyx subplanus. 



Trionyx subplanus, Schweigg. Arch. Konigsb. i. p. 289. Gray, Illustr. Ind. Zool. c. tab. 



Gymnopus subplanusj Dui7i. ^ Bibr. Erpet. gen. ii. p. 496. 



Trion^'x frenatus, Gray, Shield Rept. p. 67. 



Dogania subplana. Gray, Shield Rept. p. 69. tab. 33 (from a Japanese specimen). 



SItcU of the adult. — The bony carapace is longer than broad, much depressed along the 

 vertebral line. The anterior dorsal bone is not rugose on its surface, or but little in its 

 centre ; there is a large space not ossified between it and between the first costal. The 

 second costal is two-fifths as broad as long ; the last costal narrow. The surface of the bony 

 carapace is finely rugose, without tubercles. Sternal plates covered with skin, and only a 

 very small portion has the surface slightly rugose. 



Young sjjecimen (in spirits). — The small tubercles on the epidermis form about se^enteen 

 longitudinal series, which are close together. Brownish, marbled with yellowish and brown ; 

 head and neck with yellowish dots ; faint traces of an oblique dark streak behind each eye 

 are visible in some specimens. 



This species is found at Singapore, at Pinang, and in Japan. The shell of the largest 

 specimen in the British Museum is 10 inches long. A female individual, from Singapore, 

 with a shell only 6 inches long, had several eggs in the oviduct when captured. 



Trionyx GtJNTHERi. (Plate VI. fig. A.) 



Dogania giintlieri. Gray, Proc. Zool. Soc. 1862, p. 265. 



The bony carapace is as broad as long, and much depressed, especially along the vertebral 

 line. The anterior dorsal bone is finely rugose in its whole extent, like the remainder of the 

 shell, leaving a broad, ovate cartilaginous space behind. The second costal is nearly three 

 times as long as broad ; the last costal narrow, not much shorter than the penultimate. A 

 large portion of the middle and hinder sternal bones is rugose. 



There is only one dried specimen in the British Museum, which formerly formed part of 

 the East India Company's Collection. The shell is 7 inches long, head and neck 5 inches. 



H 



