M. F. Sumichrast on the Habits of some Mexican Reptiles. 501 



The green Iguana (/. rhinolopha, Wiegm.) resembles in size, 

 form, and colours the /. 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-bei'i^. 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 di§appearing 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 j 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 

 irregular 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. 



