64 TRIGONOCEPHALUS PISCIVORUS. 



Description. The head is triangular and very large, covered with plates in 

 front, and on the vertex, and with small scales posteriorly. The vertical plate is 

 regularly pentagonal, with an acute angle behind; the superior orbital are irregu- 

 larly quadrilateral, narrowest within, broadest without, and projecting far over the 

 eye, so as to give it a threatening appearance; the occipital plates are regularly 

 pentagonal, with acute angles forward; posterior to them is a transverse row of 

 four smaller plates; the frontal are pentagonal, large, with their outer margins 

 rounded; the anterior frontal smaller and triangular, with the bases rounded and 

 pointed forward, and the apices backwards and inwards; the rostral plate is nearly 

 quadrilateral, a little larger below. There are two nasal plates; the anterior 

 is quadrilateral, a little excavated posteriorly; the posterior is irregularly quadri- 

 lateral, concave in front, to complete the nostril. There are two anterior orbital 

 plates; the superior very large, the inferior smaller, making the posterior wall of 

 the pit between the eye and nostril, which is completed in front and below by the 

 second labial, and a small plate resting on the third labial plate. The posterior 

 orbital plates are three in number, and nearly of the same size; the inferior makes 

 part of the inferior wall of the orbit, which is completed by the third labial plate. 

 The nostrils are large, lateral, and very near the snout; a very deep pit exists 

 midway between them and the eye, but on a lower plane; the upper jaw is covered 

 with seven labial plates; the eye is large, though it does not appear so at first 

 from the projection of the superior orbital plate; the pupil is elliptical, dark and 

 vertical; the upper half of the iris bright golden, the inferior half black; the neck 

 is greatly contracted; the body elongated, very robust and thick, even to the tail, 

 where it contracts suddenly; it is covered with carinated scales, even to those 

 adjoining the plates; those above are most strongly carinated. The abdomen is 

 covered with very broad plates; the tail is short, thick, convex, and terminates in 

 a horny point, having carinated scales above, and plates and scales below. 



Colour. The head is dark brown above, with a yellowish line from the snout 

 over the nostril, tinging the outer margin of the superior orbital plate; below this is 

 a black vitta, beginning at the pit in front of the eye and continuing backwards to 

 beyond the angle of the mouth, involving the lower half of the pupil and iris. 



