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. 



• 

 Ehinoclemmys. 



The species of this very natural genus may be thus divided: — 



I. Shell black above and beloio ; steymum with a pale (when alive red ?) 



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

 each side, sometimes united in front. 



1. Rhinoclemmys melanosterna. 

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

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

 Eynys dorsalis, Spix (young) ? 



2. Rhinoclemmys scahra. 

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

 and of the crown, a diverging streak on each side of the 

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



3. Rliinoclemmys 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. fig. 3.) 



II. Shell blacJcish above and beloiv ; sternum tvith pale lateral stripes, 



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

 stripes on the side of the crown. 



4. Rhinoclemmys callocephala. 

 Geoclemmys caUocephaJa, Gray, P. Z. S. 1863, p. 254, fig. (head) ; SuppL 

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



Hah. Tropical America. 



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

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

 with a pale margin. 



5. RMnoclemmys 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. 



Hah. Tropical America. 



An adult specimen was purchased from the Zoological Society 



in the year 1864. 



