EHINOPHIS TREVELYANUS. 185 



of the head ; it is scarcely compressed above. Caudal shield large, obtusely convex, extending 

 on to the lower surface of the tail, its extent being rather more than that of the head. Anterior 

 part of the trunk surrounded by nineteen, the remainder by seventeen longitudinal series of 

 scales; ventral shields not much larger than the scales of the adjoining series, varying in 

 number from 156 to 174 ; six entire subcaudals in the male, foui- divided ones in the female. 

 Blackish olive, each scale with a ligliter margin ; prseanal scales white ; sometimes some 

 white blotches on the front part of the trunk. 



This species usually attains to a length of from 10 to 11 inches, the circumference of the 

 thickest (anterior) part of the trunk being one-ninth or one-tenth of the total length ; how- 

 ever, I have seen an example, from Sir Andrew Smith's collection, which is 16^ inches long. 

 It is found in Ceylon, and not in the Philippine Islands as stated by the French zoologists. 



Professor Peters has described another species of RMncyphis, Eh. plcmiceps (Uropelt. 

 p. 17. tab. 1. fig. 0) ; it is founded on a specimen which we received from Ceylon with Rh. 

 philijppmus, from which, in my opinion, it does not differ specifically. The depression, or 

 rather impression, of the head is not a specific character, as we often find it in some specimens 

 of a species whilst it is absent in others, and the greater breadth of the vertical shield 

 appears to me to be an individual peculiarity. In some specimens of Rh. philipinnus that 

 shield is longer than broad, in others as broad as long, and in the typical specimen of 

 Rh. planiceps it is broader than long. No other differences are observable. If my opinion 

 should be found to be correct, the name oi planiceps might be substituted for johilijjpinus, as 

 the latter term conveys a serious error. 



RhINOPHIS TREVELYANUS. 



Dapatnaya trevelyana*, Kelaart, Prodr. ii. p. 17. 



Mitylia gerrardi, Gray, Proc. Zool. Soc. 1858, pp. 58, 263. tab. 13. 



Rliinophis liomolepis, [Hemprich) Peters, Uropelt. p. 14. tab. 2. fig. 2. 



Snout acutely pointed ; the length of the rostral shield is much less than one-half of that 

 of the head; it is slightly compressed above into a rather indistinct, obtuse, longitudinal 

 keel; vertical as broad as long, or rather longer. Caudal shield large, obtusely convex, 

 extending on to the lower surface of the tail, its extent being rather more than that of the 

 head. Anterior part of the trunk surrounded by nineteen, the remainder by seventeen lon- 

 gitudinal series of scales; ventral shields not much larger than the scales of the adjoining 

 series, varying in number from 193 to 202; four or five subcaudals, partly simple, partly 

 divided into two. Ventrals and subcaudals smooth. Upper parts black, the lower parts 

 white, each scale with a black central spot ; a series of triangular white spots along each 

 side of the body ; extremity of the tail white or whitish. 



The largest specimen I have examined is 11 inches long, the circumference of the thickest 

 (anterior) part of the trunk being one-twelfth or one-thirteenth of the total length. The 

 species is a native of Ceylon, and found on the Kandyan Hills, three or four feet under ground. 



* This is tlie first name under which this species lias been described. 



2 B 



