152 CLASSIFICATION OF REPTILES. 



one eye sometimes looking forward, the other backwards, 

 sideways, or upwards. This curious fact we have re- 

 peatedly witnessed, having kept these animals alive for 

 many months : they were brought from Egypt, and 

 lived perfectly well in the hot climate of Malta. The 

 tail is long and prehensile ; and the head is generally 

 galeated, or raised in the form of a crest or hood. The 

 whole of these extraordinary reptdes are confined to the 

 hot latitudes of Africa and India, where they live en- 

 tirely upon insects, and no doubt seldom or never quit 

 the trees. The common species is said to have been 

 found in the south of Spain. 



(153.) The 1guaxii>^, or Iguana lizards, are so 

 called from the name given to many of them by the na- 

 tives of Tropical America, where the most typical exam- 

 ples are found. The group, however, is a very large 

 one, and comprehends several genera much diversi- 

 fied in appearance, but yet possessing many common 

 characters. On a partial analysis of this group, we can 

 come to no other opinion than that it accords with those 

 we have elsewhere denominated families ; and that its 

 next division is naturally into genera, and not sub-fami- 

 lies. Under this impression we shall arrange the whole 

 under the five following families, which by our analysis 

 turns out to be a perfect circle. Commencing with 

 Platydactylus, we pass, by means of the sub-genus 

 PbyUurus Cuv. to Stellio : the sub-genus Cyclura 

 leads us (probably by Amblyrhynchus) to the two types 

 of Iguaxa ; namely, Basiliscus and Iguana proper: 

 Ophryessa passes into Polychrus by means of Brnchy- 

 lophus : Norops again leads us to Axolis ; from which, 

 by means of Stenodactylus , we return again to Platy- 

 dactylus. 



(154?.) The Platydnctyli are the geckos, or nocturnal 

 lizards. Their flattened form and broad head gives to 

 these reptiles a very striking and a peculiarly disagree- 

 able appearance ; hence, although timid and harmless, 

 they are always regarded by the vulgar as venomous and 



