98 HETERODONPLATIRHINOS. 



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 

 these frontals, so as to prevent them coming in contact with each other, is a 

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

 plate, with a ridge on its upper surface continuous with that of the rostral plate. 

 The rostral plate is triangular, with its basis below and the apex very pointed 

 above, and recurved, with a strong carina or ridge on the upper surface. The 

 nostril plates are two on each side; the anterior is irregularly quadrilateral, 

 lunated on the posterior margin, with its anterior and inferior angle greatly 

 prolonged; the posterior is narrow, and concave in fi-ont to complete the nostril. 

 There are twelve orbital plates, the superior of which have been already described. 

 Besides these, there are three anterior orbital plates, which are quadrilateral, the 

 largest being above; the inferior orbital are five and the posterior orbital three in 

 number, all of which are quadrilateral. The upper jaw has six lateral plates, 

 quadrilateral, and increasing in size to the sixth, which is longest. The nostrils 

 are very large, near the snout, and lateral. The eyes are large; the pupil dark, 

 the iris light gray. The neck is nearly the size of the head when he is quiet, but 

 when roused or irritated he flattens it more than twice its ordinary breadth. 

 The body is elongated, thick, rounded above, but flattened at the abdomen, 

 covered with scales strongly carinated above, the three inferior lateral rows being 

 ecarinate, and with plates below. The tail is long, narrow, and terminating in a 

 point, with scales or bifid plates on its under surface. 



Colour. The head above is dusky, with a light band between the orbits; 

 behind the occiput is a dark spot; a dark band begins at the back of each nostril, 

 which increases in size as it descends, and forms a large blotch on the side of the 

 neck. The body is olive-brown, or sometimes brownish-yellow, and marked with 

 a triple series of black or dark gray spots; those of the vertical series being 

 subquadrate and elongated transversely; the spots of the lateral rows are rounded, 

 and many of them correspond with those of the vertebral line, while others 



