158 Dr. J. E. Gray on Chinese Mud- Tortoises. 



The middle of the front of the back covering the oblong 

 bony shield marked down its centre on each side with diver- 

 ging, more or less elongate, transverse lines. On the sides 

 of the broad central convex part of the back there are a 

 number of short parallel longitudinal lines, placed in clusters 

 between the diverging lines of elongated spots on the sides of 

 the middle of the back. 



The head, neck, and upper part of the limbs blackish olive 

 above and yellow below, the underside of the hinder margin 

 of the disk and the sternum more or less varied with lead- 

 colour. The upper part of the head to the occiput with close, 

 very irregular-shaped yellow spots, which are somewhat alike 

 on each side, but can scarcely be called symmetrical. The 

 sides of the neck and chin yellow, with narrow olive reticula- 

 tions. The back of the neck and the upperside of the legs 

 and feet olive, with numerous small yellow dots, giving it a 

 mottled appearance. Tail very short, conical. 



Skull 2 J inches long, and 2 inches wide, very like Trionyx 

 gangeticus in external appearance ; but the palatal groove in 

 front of the internal nostrils is very wide, and gradually nar- 

 rowed and rounded in front ; indeed the internal edges of the 

 upper alveolar surface form continuous converging lines from 

 the back to the front of the broad concave palatal groove. The 

 alveolar surface of the lower jaw slightly concave in the front 

 half; the centre of the front with a very slight longitudinal 

 elevation, which is most visible on the outer edge ; the sides 

 deeply concave, with a well marked inner and a more elevated 

 outer edge. 



The palatal groove is very broad and short, as in Trionyx 

 gangeticus^ but is wide behind and rather nan'owed in front, 

 very unlike the narrow, deep, much longer groove of T. Leithii. 

 The alveolar surface of the lower jaw differs from that of T. 

 gangeticus in being slightly concave in front without any pit on 

 each side of the keel in the centre of the hinder margin. 



The specimen sent had the front and hind legs of the left 

 side tied together by a string passed through the web of the 

 feet, as if this were the way in which the Chinese fishermen 

 prevented the specimen from escaping after it was caught, as 

 it would cause the animal to constantly progress in a small 

 circle. This seems to be the common way of the fishermen ; 

 for I find the feet of several other specimens of Mud-Tortoise 

 so united. Length of dorsal disk 12 inches, width 10^ inches. 



This is the most beautiful species of Trionychidse that has 

 yet occurred, and most distinct by its beautiful coloration ; 

 the lines on the back have some resemblance to Chinese 

 printing. 



