Mr. 0. Salvin on some new Reptiles from Guatemala. 335 



to the base of the head, the ventral margin for nearly half its length. 

 The head is very obtuse and rounded, terminating anteriorly in a 

 short, sharp beak. The rami or inferior antennae are of considerable 

 size, and the setae or filaments are finely plumose. The sixth seg- 

 ment of the body of the animal has five or six projections from it, 

 two or three of which are small and rough, with very minute spines. 

 The first is the longest, being prolonged and curved upwards ; the se- 

 cond is large and well marked ; and between the last and the hooks 

 in which this segment terminates, the edge is beset with numerous 

 small spines, the inferior six or seven being much the largest. 



I have named this Daphnia after my late friend Mr. George New- 

 port, to whom I am indebted for the specimens sent to me several 

 years ago. 



Hab. India. 



On two new Reptiles from Guatemala. By Osbert 

 Salvin, M.A., F.Z.S. 



Thamnocenchris, n. g. (Crotalid^e.) 



A pit on each side of the face. Posterior part of the body and 

 tail much compressed, the latter ending in a horny spine. Sub- 

 caudals one-rowed. Tail prehensile. Head angular, anteriorly 

 covered with irregular shields, and having small keeled scales poste- 

 riorly. No small scales between the superciliary and the orbit. The 

 second upper labial forms the anterior part of the facial pit. 



Thamnocenchris aurifer. 



Scales keeled, in nineteen rows. Nine upper labial shields. Small 

 shields between the fourth labial and the orbit. Green, with a dorsal 

 series of orange spots edged with black. A black band from the 

 orbit to the side of the occiput. 



Hab. Cohan, Vera Paz. 



This new form is distinguished from Teleuraspis (Cope) by its 

 peculiarly compressed body and tail, the latter being coiled as in 

 some of the Boidce, clearly indicating a habit of living in trees. It 

 also differs from Botriechis'^, Peters, in having very large shields 

 instead of very small scale-like ones on the upper surface of the 

 snout. Nor does Prof. Peters mention in his description the pecu- 

 liarly compressed tail, the most striking character of the present 

 genus. The general form of the head is similar to that of Cenchris, 

 which it moreover resembles in having the anterior portion of the 

 upper surface of the head covered witli irregular shields of moderate 

 size. Nostril in the middle of a single plate. Upper labials nine, 

 the third, fourth, and fifth of which are the largest. There are about 

 seven small shields between the orbit and the fourth and fifth. From 

 the superciliary backwards the head is covered with keeled scales. 

 Scales of the body keeled in very oblique series. 1 54 ventral shields ; 

 anal entire ; .53 caudal shields. The posterior ventral shields extend 

 very far up the sides. Colour green, paler and yellower below. A series 

 * Monatsb. Akad. Wiss. Berlin, 1859, p. 278. 



