Dr. J. E. Gray on a new Species of Freshwater Tortoise. 501 



hairs, each of which is marked with abroad subterminal yellow band. 

 These black hairs are more abundant, and have broad pale rings on 

 the rump outside of the thighs, and especially on the lower part of 

 the tail, where they nearly hide the general red colour. The terminal 

 half of the tail bright chestnut-brown, without any black hairs or 

 pale rings. The throat, breast, belly, lower part of sides, inner side 

 and edge of the legs, uniform bright red-brown. Ears rounded. 

 Whiskers black. Feet covered with short close-pressed hairs. 

 Hab. Siam (M. Mouhot). 



DESCRIPTION OF A NEW SPECIES OF FRESHWATER TORTOISE 

 FROM SIAM. BY DR. J. EDWARD GRAY, F.R.S., V.P.Z.S. 



The British Museum has received from M. Mouhot, with some ' 

 other Reptiles, two specimens of a Freshwater Tortoise, which are 

 decidedly different from any I have before seen. They have some- 

 what the external appearance, both in shape and markings of the 

 head, of some specimens of Cistudo amboinensis, but belong to the 

 genus Emys, or rather Geoclemys, and not to Cistudo. 



They are referable to the first division of genus which has the back 

 of the shell three-keeled, and, like the other species of that section, 

 come from Asia. 



GEOCLEMYS MACROCEPHALA. 



The shell oblong, rather depressed, entire, three-keeled, olive- 

 brown ; the keels subcontinued, nearly parallel, the middle one higher 

 and more distinct behind ; the lateral ones, near the upper edge of the 

 shields, continued, ending abruptly on the hinder edge of the third 

 lateral discal shield ; the hinder lateral and central shield only 

 marked with a slight convexity; the margin entire, yellow-edged. 

 The under side yellow, with black triangular spots ; the sternum flat, 

 very indistinctly keeled on the side. 



Animal blackish-olive. Head large ; crown flat, covered with a 

 single smooth plate, purplish-brown, with two streaks from middle 

 of the nose, the upper edging the crown, the other the upper part of 

 the beak, and with two streaks from the hinder edge of the orbit, 

 the lower short and interrupted, extended on the temple, the upper 

 broader and continued over the ear along the side of the neck ; two 

 close streaks under the nostrils to the middle of the upper jaw, and 

 two broad streaks, dilated behind, down the front of the lower jaw, 

 and continued on the edge of the lower jaw behind ; the nape and 

 hinder part of the side of the lower jaw covered with large flat scales ; 

 the rest of the neck and legs covered with minute granular scales ; 

 the front of the fore-legs covered with broad band-like scales ; the 

 toes of the fore- and hind-feet rather short and thick, covered above 

 with broad band-like scales. 



Hab. Siam. 



The front vertebral plate is quadrangular, the front edge wider, 

 rounded ; second, third, and fourth ventral shields six-sided, the 

 second longer than broad, the fourth broader than long ; the three 



