54 DR. J. E. GRAY ON THE TRIONYCHID^E. [Jail. 7, 



identical with that species. The skin shows the white spots on the 

 underside of the head. 



1. Landemania perocellata. (Fig. 6, p. 53.) 



Head olive above, with a black streak from the back edge of the 

 eye, extending along the upper part of the sides of the neck. 



Trionyx perocellatus, Gray, Cat. Tort. B. M. p. 48 ; Cat. Sh. Rept. 

 p. 65, t. 31 (animal in spirit). 



Potamochelysl perocellata, Gray, P. Z. S. 1864, p. 86. 



Landemanial perocellata, Gray, P. Z. S. 1869, p. 216; Suppl. 

 Cat. Sh. Rept. p. 96 ; Ann. & Mag. Nat. Hist. 1872, x. p. 338. 



Landemania irrorata, Gray, P. Z. S. 1869, p. 218, fig. 18; Suppl. 

 Cat. Sh. Rept. p. 96, fig. 31 (sternum, from dried specimen). 



Trionyx tuberculatum, Cantor's drawings, Gray, P. Z. S. 1861. 



Potamochelys tuberculatus, Gray, P. Z. S. 1864, p. 87 ; Suppl. 

 Cat. Sh. Rept. p. 105. 



Hab. China (Chusan). 



The specimen figured in the Cat. Sh. Rept. has the head olive, 

 with a few irregular black spots, with a long narrow streak from the 

 back edge of the eye, and two or three streaks from the lower edge 

 of the eye towards the lips ; front extending towards the nostrils ; 

 lips and throat with large white spots ; dorsal disk smooth (in 

 spirit), the odd bone united to the rest of the disk ; four sternal 

 callosities distinctly marked, but the front odd bone is smooth. 



The dorsal disk convex, with a longitudinal depression on each 

 side of the central linear prominence ; the odd bone large, trans- 

 verse, united to the whole length of the dorsal disk. 



There is a specimen in the British Museum with the sternal cal- 

 losities not so much developed ; and the odd bone in front of the 

 sternum, which is V-shaped, has short arms,, not so long as the 

 breadth of the triangle. It is smooth, and not marked with callosi- 

 ties ; but otherwise the two specimens are exceedingly alike. 



The skull of the specimen described as Landemania irrorata 

 is tapering in front ; between the transverse nose-hole and the orbit 

 about half the length of the diameter of the orbit ; palate with a 

 broad shallow impression between the front and the nostrils, which 

 becomes narrower behind ; alveolar surface broad, especially behind. 

 Lower jaw produced in front, triangular, sides rather concave ; alve- 

 olar surface concave, broad in front, with a slightly elevated central 

 longitudinal ridge, rather narrower on the sides behind, and deeply 

 concave, with a strong ridge on the outer side. 



Length from nose to condyle 2\ inches. 



A skeleton of a specimen received from Mr. Swinhoe. The front 

 bone of the dorsal shield very wide, nearly as wide as the second bone, 

 united through its whole length to the second bone ; front pair of 

 bones to the sternum sub cylindrical ; the pair of lateral bones on the 

 sternum united together by a minutely dentate suture. 



Dr. Cantor's drawing, which I had described as Trionyx tubercu- 

 latus and Potamochelys tuberculata in the Cat. Sh. Rept. p. 105, is 

 most probably only a variety of this species. 



