GENERA OF THE IGUANA LIZARDS. 15S 



highly dangerous. Besides the depressed form of the 

 body^ they are eminently distinguished by having the 

 feet palmated, or rather lobed and dilated into disks, 

 analogous to the coots and phaleropes among birds, and 

 to the crocodiles among reptiles : the toes, which are 

 of nearly equal length, are generally terminated with re- 

 tractile claws like those of rapacious animals ; in the 

 present case, however, this structure is not intended to 

 secure their prey, which merely consists of weak insects, 

 but to enable them to gain a firmer grasp. These dis- 

 gusting little creatures are very commonly seen in Italy, 

 running during night or in cloudy weather on the top of 

 the ceilings of old mansions. The eyes are very large, 

 and the pupil contracts from the influence of light like 

 those of a cat : the jaws have a range of very small 

 crowded teeth, but there are none in the palate : the 

 skin resembles shagreen, and the eyelids, which are very 

 short, give to their physiognomy a striking and pecu- 

 liar aspect : the tail has circular folds, like that of the 

 genus Anolis. 



(155,) The genus Stellio has the depressed head and 

 body of the geckos, and much of the same forbidding 

 appearance ; but their toes are not lobed, and their tails, 

 although sometimes broad, are encircled by rings of 

 strong spiny scales, which gives them a very peculiar as- 

 pect. The passage to these from the last group is beauti- 

 fully marked by the broad-tailed lizard of New Holland; 

 then com.es the Indian Uramastrix, and the true stellios 

 of Africa : the fourth sub-genus appears to be Cyclura 

 Cuv., but we have not been able to determine the fifth. 

 All these have a narrow neck, and in most cases a head 

 much enlarged behind. 



(156.) The next genus is Iguana proper: it is 

 immediately to be distinguished from the last by the 

 attenuated and ringless structure of the tail, by the pre- 

 valence of dorsal crests upon the back, and by the posses- 

 sion of palatine teeth. In one of the sub-genera (Basi- 

 liscus) the hind head is enlarged^ as if it was covered 



