May, 1845.] 241 



Description of Reptiles from South America, supposed to be New. 

 By Edward Hallowelx, M. D. 



Coluber Spixii. 



Description. — Head elongated, large, covered above with nine plates; the 

 rostral plate is large, pentagonal, incurvated below, the upper extremity is 

 rounded ; the anterior frontals are large, quadrangular ; the posterior frontals 

 are larger than the anterior; they are pentagonal; the vertical plate is large, 

 pentagonal, broad anteriorly, the sides incurvated to receive the margin of tbe 

 superior orbitar plates ; the superior orbitar are large, pentagonal, the posterior 

 margin the broadest; the occipital plates are large, pentagonal, and are joined 

 anteriorly to the vertical, ihe supra-orbitar, and the post-ocular plate; there are 

 two nasal plates with the nostril placed between them; there isone loral plate ( $ ) 

 which is quadrangular; the anterior orbitar plate is large and also quadrangular, 

 the upper margin broader than the inferior ; there are two post-ocular plates, 

 both of which are quadrangular ; there are eight superior labial plates, the se- 

 venth and eighth the largest; the eyes are large and projecting; irides ; 



body long, somewhat slender, thickest near the middle; tail long; body covered 

 above and on the sides with large quadrangular scales, which are smooth ; the 

 scales upon the tail are also smooth, quadrangular. 



Abdominal scuta 164 : subcaudal 113. 



Colour. — Upper part of head sea-green ; this colour predominates upon the 

 sides as far as the inferior margin of the orbit; margin of upper jaw straw 

 colour; upper part and sides of body and tail also sea-green ; the chin, throa, 

 and under part of body and tail are straw colour. 



Dimensions. 



Length of head, 

 Greatest breadth, 

 Length of body, 

 Length of tail, 



CoLUBEK fllSCUS. 



Description. — Head of moderate size, elongated, covered above with nine 

 plates ; the rostral plate is hexagonal, rounded above ; the anterior frontals are 

 of moderate size, pentagonal ; the posterior frontals are larger than the anterior, 

 pentagonal ; the vertical plate is long, pentagonal, broad anteriorly ; the supe- 

 rior orbitals are quadrangular, the posterior margin somewhat rounded ; the 

 occipital plates are large, pentagonal, they are joined anteriorly to the vertical, 

 the supra-orbitar, and the upper post-ocular plate; there are two nasal plates, 

 which are rather large, with the nostril placed between them ; there is one ant- 

 ocular and two post-ocular plates ; the anterior is larger than either of the pos- 

 terior, its anterior margin the broadest; there is one loral plate, which is long 



and quadrangular ; the eye is large and projecting; irides ; there are nine 



superior labial plates, the seventh and the eighth are the largest ; the neck is 



