34 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 
regularly 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 quadrilateral, 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. 
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 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 view, 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, 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. 
Cotour. The head is dark brown above, with a yellowish line from the snout 
’ y 
