74 CROTALUSMILIARIUS. 



Description. The head is very large, triangular, broad behind, and truncate at 

 the snout; covered with plates in front, and on the vertex to behind the eyes. The 

 vertical plate is pentagonal, broadest in front, pointed behind; the superior orbital 

 is oval, most extensive in the antero-posterior direction, with its outer margin 

 projecting greatly over the eye. The occipital plates are rhomboidal; behind these, 

 the head is covered with small scales. The frontal plates are pentagonal, broadest 

 externally; the anterior frontal are triagonal, with their bases outwards and for- 

 wards; the nasal plates are quadrilateral and nearly of the same size, the one 

 hollowed on its posterior, the other on its anterior border, to form the nostril. 

 There are two posterior orbital plates quadrilateral; and two inferior, of which 

 the posterior is very long and narrow. The anterior orbitals are two in number, 

 the inferior of which makes the upper wall of a deep pit that exists midway 

 between the nostrils and eyes, but on a lower plane; the inferior margin is com- 

 pleted by two other plates. The upper jaw is covered with twelve labial plates; 

 the nostrils are large and very near the snout, but lateral; the eyes are large, the 

 pupil black, oval, and vertical; the upper half of the iris of the brightest yellow, 

 lower half black. The mouth is large; the jaws strong; the upper furnished with 

 poisonous fangs. The neck is greatly contracted, and covered Avith small carinated 

 scales; the body is elongated, but thick in proportion, even to the tail, where it 

 becomes suddenly contracted, and is covered with carinated scales above, the 

 lowest row ecarinate. The tail is short, conical, and sustains an uncertain number 

 of rattles. 



Colour. The ground of the colour of the whole upper surface of the animal 

 is pepper-and-salt grey. The head is more dusky in front, with a light coloured 

 band running transversely from orbit to orbit; from this transverse band begins a 

 yellowish-red, or sometimes a purplish vertebral band, that runs to near the 

 extremity of the tail; this band increases in size to the neck, and has on either 

 side of it, at the occiput, an oblong dark blotch; from the superior orbital plate to 

 the posterior part of the head is a dash of yellowish-white; beneath this, and 

 descending from behind the orbit, is a black vitta, under which is again a yellowish- 

 white line from the inferior margin of the orbit to behind the angle of the mouth. 



