144 Dr. J. E. Gray on Tortoises. 



dorsal plates are pale, with a darker edge and a dark diffused 

 spot in the middle of the areola ; the front sides of the upper 

 part of the marginal plates are brownish ; the sternum is varied 

 with diffused black marks ; the caudal marginal plate is marked 

 with a central groove. 



Khinoclemmys. 

 The species of this very natiu-al genus may be thus divided: — 



I. Shell black above and below ; sternum ivith a pale {ivhen alive red ?) 



lateral stripe. Costals not spotted. Head black, with a streak on 

 £ach side, sometimes united in front. 



1. RMnocleinmys melanosterna. 

 Head black, with a white streak on the side of the nose and 

 head. (Gray, P. Z. S. 1870, p. 722, fig. 1.) 

 Emys dorsalis, Spix (young-) ? 



2. Rhinoclemmys scabra. 

 Head black, with a small spot on each side of the nose 

 and of the crown, a diverging sti-eak on each side of the 

 head, and a round spot on the occiput. (Gray, I. c. fig. 2.) 



3. Rhinoclemynys lunata. 

 Head black, with a spot on each side of the nose and occiput, 

 and a streak on each side of the head, united across the fore- 

 head. (Gray, I. c. ^g. 3.) 



II. Shell blackish above and below ; sternum with pale lateral stripes, 



with a spot on each side of the nose and numerous longitudinal 

 stripes on the side of the crown. 



4. Ridnoclemmys callocephala. 

 Geoclemmys callocephala, Gray, P. Z. S. 1863, p. 254, fig. (head) ; Suppl. 

 Cat. Shield Kept. p. 23, fig. 10 (head). 



Hab. Tropical America. 



III. Shell olive above, with a pale spot in the centre of the areola of 

 each costal, surrounded by pale rings in the young; beneath black, 

 with a pale margin. 



5. Rhinoclemmys frontalis, n. sp. 



Head dark olive, nose with a narrow central streak above 

 and a narrow streak on the lateral margin extending to over 

 the orbits. 



Hab. Tropical America. 



An adult specimen was purchased from the Zoological Society 

 in the year 1864. 



