AGAMA CZELATICEPS. 
situated on the upper surface, and one on each side. The scales on the under 
surface of the tail are arranged so that the keels form almost continuous 
narrow ridges. The scales of the under surface of the head are generally 
smooth, those of the under parts of the neck, and of the breast and belly, 
triangular and keeled, the keels prolonged beyond the scales, forming fine 
spines. Scales of the extremities triangular and strongly keeled, those of the 
under and anterior surfaces smallest ; on the upper and hinder surfaces some 
large aculeated scales. 
The only specimens of this species which I have seen were obtained towards the tropic of 
Capricorn. It inhabits dry, arid situations, is very watchful, and when approached attempts 
by gestures, particularly of its head, to stay the advance of the intruder, but failing that 
it takes to flight, and conceals itself as it best can. In this manner of proceeding it agrees 
with other species of the genus which I have had the opportunity of observing, all of whom 
employ gesticulations of the head and dilatation of the throat, apparently with the hope of 
creating fear in those approaching them : whoever has observed the use a monkey makes of 
its head when it is approached or closely surveyed by a stranger, will readily comprehend 
the practice of the lizards referred to. The embossed condition of the scales, particularly 
of those of the upper surface of the head, well shown in figure a, furnishes at once the 
means of distinguishing it from the species hitherto described. 
