118 



SAUEIANS. 



The name Iguana was given by Laurenti to a heterogeneous group 

 of Saurians, various forms being included which were first separated 

 by Daudin. The Iguanas, as thus restricted, are characterized by a 

 very large thin dew-lap under the neck, a double row of small 

 palatal teeth, and a crest on the back and tail ; the latter long, 

 slender, compressed, and covered with small imbricated and cari- 

 nated scales. Messrs. Dumeril and Bibron describe the genus, thus 

 modified, as principally remarkable for the cutaneous prolongation 

 which constitutes the deep and thin dew-lap, or pouch, the free 

 border of which describes a curved line, and is dentated at the part 



Fig. 28. — Iguana tuberculata. 



nearest the chin. The head is moderately long, and has the form 

 of a pyramid with four faces. The neck is slightly compressed, 

 the limbs long, the toes unequal and sometimes denticulate on the 

 edge. The five toes of the posterior feet are graduated ; the tail, 

 which is long and slender, is slightly flattened from right to left. 



