108 
fifteen across the tail, each streak being darker towards the head, and 
gradually shaded off towards the tail. These streaks extend over the 
dorsal and caudal crests, which partake entirely of the variegations 
of the body in the younger, but, in the older individuals, are tipped 
with red and yellowish brown at their bases and extremities. These 
black streaks do not unite under the belly or under the anterior part 
of the tail, hut towards the extremity of the tail they gradually elon¬ 
gate and become more dull, encircling the tail, and at last becoming 
hardly discernible, mixing with the green or grey into one dull tint. 
The dewlap, as well as the folding skin in front of the shoulder, 
connected noth it, is interspersed with black and yellowish brown, of 
which colours the denticulations of the dewlap also partake. The 
upper part of the head is of a darker and richer green in the young, 
fading as the animal advances in years, and becomes weather-beaten, 
as is the case with the human species, and with all animal and vege¬ 
table life. The whole of the under part of the body is of a lighter 
colour in both old and young. The female has a more delicate colour 
and general appearance than the male. 
Whilst always retaining the same colours, this Iguana has the power 
of considerably changing his hues, but these changes are gradually 
performed. The colours become more dull as the period of the 
change of skin approaches, which is not, however, frequent. Each 
scale has its own tint, and the colours being thus irregularly blended, 
an appearance is given, particularly to the younger reptiles, very much 
like that of worsted-work. The colour of the eye is dark brown, the 
pupil being surrounded by a golden rim. 
Every part of this curious reptile is covered with scales, and these 
are of every variety of shape and size. Those on the top of the head 
are large, smooth, and unequal; between them and the mouth rims 
a row of smaller scales, while the mouth itself is surrounded, both in 
the upper and lower jaw, by large scales terminated at the extremity 
between the nostrils, by one large brownish and softer scale in the 
upper jaw, and a similar though smaller scale meeting it in the lower 
jaw. From this latter, and below those immediately 7 surrounding the 
mouth, is a range of scales or rather plates, each larger than its pre¬ 
decessor, terminated on either side by 7 a very 7 large plate under the 
auricle. Below this row of scales is the gular pouch (Fanon) covered 
by small, smooth scales. The eye is protected above by 7 small, smooth, 
unequal scales, which also form part of the covering of the top of the 
head. The scales of the lower eyelid are peculiarly small and deli¬ 
cate ; and a row of semispherical scales, resembling somewhat a string 
of small pearls on each lid, surrounds the eye. At the back of the 
head the scales become tuberculous, and a few on each side of the 
neck assume a pyramidal or rather a conical form. The scales of 
the neck and back are almost circular, but nearer the tail they become 
rhomboidal and carinated, their posterior points elongating, and their 
centres projecting more and more, both above and below, as they' reach 
the extremity of the tail, so as to give it the form of a many-edged 
saw, the most severe edge being that presented by 7 the caudal crest. 
The scales above the fore-legs are equal, carinated, and imbricated. 
