LIOPHIS MERREMI. 159 



LlOPHIS MERREMI, "Wagl. 

 (Plate XI, figs. 1-6.) 



OBSERV. There was but one specimen of this species collected, 

 thirteen inches and a half in length, and consequently immature. It 

 is the Coluber doliatus, of the Prince of Neuwied, now generally con- 

 sidered as a mere variety of coloration of C. merremi, of the same 

 author. For its synonymy we refer to the " Erpetologie generale," 

 of Dumeril and Bibron. 



DESCR. The head is quite depressed, subovoid when viewed 'from 

 above. The snout is obtusely rounded, and projects somewhat beyond 

 the lower jaw. The nostril is situated between two plates. The 

 eyes are of moderate development, and circular in shape. The mouth 

 is deeply cleft, concave posterior to the eye, and ascending towards its 

 angle. The occipitals are moderately developed, tapering posteriorly 

 into an acute angle. The vertex plate is as long as the occipitals, elon- 

 gated, five-sided, slightly concave laterally, acute-angled posteriorly, 

 engaging between the occipitals. The supraoculars are shorter than the 

 vertex plate, narrower anteriorly than posteriorly, and slightly arched 

 above the eye. The postfrontals are angular, much larger than the pre- 

 frontals, and sending a process to the loral region. The prefrontals are 

 subangular. The rostral is semi-elliptical, concave beneath, elevated 

 so as to be seen in an upper view of the head. The nasals are well 

 developed, equally perforated by the nostril; they are superiorly acute, 

 and may be seen in an upper view of the head : the prenasal between 

 the rostral and the prefrontal, and the postnasal between the prefron- 

 tal and the postfrontal. The loral is trapezoid, its longest diameter 

 being obliquely vertical. There is but one anteorbital, very narrow 

 inferiorly, widening superiorly, and sending a triangular process to 

 the upper surface of the head, nearly contiguous to the anterior margin 

 of the vertex plate, between the postfrontal and the supraocular. We 

 observe two postorbitals, the inferior one being smaller than the upper. 

 There are two elongated temporal shields, placed one behind the other, 

 and contiguous to the occipital plate. The upper labials are eight in 

 number on the right side, and nine on the left ; they increase in size 

 from the rostral backwards ; the sixth and seventh or seventh and 



