67 



HETERODON PLATIRHINOS.— La^m7/e. 



Plate XVII. 



Characters. Head short, flattened, triangular, turned up and pointed at the 

 snout, a strong ridge on the rostral plate above; body greyish or yellowish-grey 

 above, with large blotches or transverse bars or oblong spots of black; abdomen 

 dirty-white. PI. 144. Sc. 42. 



Synonymes. Coluber heterodoo, Latreille, Hist Nat. Rept., torn. iv. p. 32, figs. 1, 2, 3. 

 Coluber heterodon, Daudin, Hist. Nat. des Rept, torn. vii. p. 153, fig. of head, pi. Ix. 



fig. 28. 

 Coluber heterodon, Say, Amer. Jour. Arts and Scien., vol. i. p. 261. 

 Coluber heterodon, Harlan, Med. and Phys. Res., p. 120. 

 Hog-nose Snake, Vulgo. 



Description, The head is large, flat, triangular, broad behind, with the snout 

 pointed and elongated at the tip; it is covered with scales on the posterior part, 

 and with plates on the anterior and on the vertex. The vertical plate is regularly 

 pentagonal, with its broadest part directed forwards; the superior orbital are 

 quadrilateral, elongated, and broadest posteriorly, with their outer margins pro- 

 jecting over the eye, which gives a sinister look to the animal. The occipital 

 plates are rhomboidal. The frontal are quadrilateral, with their anterior inferior 

 angles very much prolonged; the anterior frontal are triangular, with their bases 

 directed inwards, and their apices rounded and turned to the nostrils. Between 

 the anterior frontal, to prevent them coming in contact with each other, is a 

 narrow, elongated, azygous plate, reaching from the posterior frontal to the 



