113 



COLUBER AM^NUS.— %. 

 Plate XXIII. 



Characters. Head short; snout truncated; neck not contracted; body slender, 

 covered with smooth scales, above light chestnut-brown, opalescent in some 

 lights; abdomen bright salmon-colour. PI. 120 — Sc. 35. 



Sfnonymes. Coluber amsenus, Say, Jour. Acad. Nat. Sci. Phila., vol. iv. p. 237. 

 Coluber amsenus, Harl., Med. and Phys. Res., p. 118. 



Description. The head is small; the snout broad and but slightly rounded; 

 the vertical plate is very broad, triangular, with its basis rounded, directed 

 forwards, and its apex backwards; the superior orbital is small, subtrapezoidal, 

 and slightly concave at its external border; the occipitals are pentagonal and 

 very large, covering nearly one-half of the superior surface of the head; the 

 frontals are quadrilateral, broad, and most extensive transversely; the anterior 

 frontals are small and oblong; the rostral is very short, rounded above and 

 concave below; the nasal plate is single, quadrilateral, with the nostril nearly in 

 its centre, and opening laterally; the anterior orbital is large, and a parallelogram 

 in form; the posterior is pentagonal, and much smaller; and behind this are two 

 oblong square temporal plates; the inferior wall of the orbit is completed by the 

 third and fourth labials, of which plates there are six, the two anterior quadri- 

 lateral, the third and fourth pentagonal and larger, the fifth quadrilateral and 

 largest of all. The eyes are small and exposed; the pupil black, with the iris 

 dusky. The neck is not contracted. 



The body is cylindrical, robust for the size of the animal, and covered with 

 Vol. IV.— 15 



