M. F. Sumichrast on the Habits of some Mexican Reptiles. 501 
The green Iguana (I. rhinolopha, Wiegm.) resembles in size, 
form, and colours the J. tuberculata of Brazil: like the latter, it 
has the sides of the neck sprinkled with conical tubercles, a large 
scale under the tympanum, and a crest upon the back and the 
neck ; but it is distinguished from that species by the presence 
of three or four raised'scales upon the muzzle. The general 
colour of the body is a darker or lighter green, with broad, 
irregular transverse bands of a dark colour; the lower parts are 
yellowish. In very old individuals, the tail acquires a fine 
blood-red tint. 
The maxillary teeth of the Iguanas are finely serrated on 
their margins: this structure is connected in these reptiles with 
an exclusively herbivorous, or, properly speaking, phyllophagous 
diet. In the stomachs of the individuals which I have prepared 
I have never found anything but leaves or the remains of soft 
berries, such as those of the Goula-beri*. The intestinal sac 
sometimes attains an extraordinary development, in consequence 
of the quantity of leaves which are packed into it. 
The Black Iguana (Cyclura acanthura, Wiegm.) varies much 
in the number and intensity of the spots or bands with which 
the ground-colour is marked. The following description, taken 
from a fresh specimen, may give an exact idea of the typical 
coloration of this species. 
Male.—The general colour is a clear silvery grey, brighter on 
the upper and lateral parts of the body, where the spots are 
more distant, and almost disappearing under the numerous 
confluent dark spots which cover the limbs. The upper part of 
the head, the throat, and the lower part of the legs are sprinkled 
with small irregular blackish spots; the rostral scales are en- 
tirely of this colour. From the posterior margin of the tympanic 
aperture a long and large spot, formed by the agglomeration of 
numerous small ones, covers the shoulder as far as behind the 
anterior legs. From this spot to the origin of the tail there are 
six black transverse bands, formed, on the flanks, of confluent 
spots; these, after separating each into two branches, unite, on 
the median line of the back, with those of the opposite side. 
On the upper part of the chest is a large spot of a fine black 
colour, which occupies nearly the whole space between the fore 
legs. As has been said, the limbs are so much occupied above 
by the black spots as to appear of the latter colour, with a few 
regular rings formed of light spots. The contrary is the case 
* This shrub, which is very abundant in the western parts of Mexico, 
produces berries, of a saccharine taste and of a viscous consistency, which 
are employed in the manufacture of indigo (anil), for the purpose of acce- 
lerating the fermentation of the plant and the precipitation of the colouring 
matter. 
