NOTOCHELYS PLATYNOTA. 17 



NOTOCHELYS, Gray. 



Thorax and sternum solid, entirely bony; sternum without transverse 

 joint ; a cartila2;inous longitudinal suture between sternum and upper shell. 

 Upper shell angular; sternum flat; the suture between the pectoral and 

 abdominal ])lates straight. Legs covered with very small scales, fingers and 

 toes with small transverse shields. Fingers and toes broadly webbed. 



Only one species is known. 



NoTOCHELTS PLATYNOTA. The Flat-backed Emys. 



Emys platjTiota, Gray, Proc. Zool. Soc. 1834, p. 54; Illustr. Ind. Zool. tab. 

 Notochelys platynota, Gray, MS. 



Form and Plates. — This species may be very easily recognized by its flat hack, and by the 

 increased number of vertebral plates, of which there are six instead of five ; a very young 

 specimen 2^ inches long, from Singapore, has seven vertebrals. The additional vertebral is 

 intercalated between tlie last and the penultimate ; it is very much smaller than any of the 

 others. Each vertebral, and in half-grown specimens each costal also, has the areola 

 elevated, these prominences forming an interrupted keel along the vertebral line. The five 

 anterior vertebrals are much broader than long ; the second, third, and fourth quite flat ; 

 the sixth polygonal, compressed into a ridge along its middle. The anterior and posterior 

 margins of the shell are strongly serrated, the anterior less than the posterior. Sternum 

 subtruncated in front and behind. Gulars longer than broad, the suture between them 

 longer than that between the postgulars ; pectorals and abdominals equal in length ; anals 

 subquadrangular, the suture between them being longer than one of the hind margins, 

 which together form a nearly straight line. 



JJjyper jaw with a pair of tooth-like prominences separated by a deep groove ; the 

 remainder not denticulated. Front part of the fore leg with broad band-like transverse 

 shields, wrist and heel with large scales. Fingers and toes broadly webbed ; claws elongate, 

 strong. 



Colour. — Yellowish brown above, with brown streaks radiating from the areolae. Sternum 

 yellowish, with the areolar portions more or less brown. Head yellowish, with brown 

 specks. Neck brown, with irregular yellow lines along the sides. A half-grown specimen 

 from Singapore has a brown spot on the areola of each costal plate, and a pair of brown spots 

 on the same portion of the vertebrals. 



The largest specimen I have seen has a shell 10 inches long. The only well-authenticated 

 locality inhabited by this species is Singapore, whence it has been brought by Mr. Wallace. 



D 



