CLASS III. IIEPTILIA: ORDE]i 3. SAURIA. 



379 



THE IGUANIDJE. 



These constitute anotlicr exceedingly numerous family. They are frequently of considerable 



size ; the head is unusually broad aiul 

 flattened, and often furnished with comb- 

 like ridges or membraneous lobes, and 

 similar appendages are usually continuc(l 

 along the back. The throat, also, is al- 

 most always furnished with membraneous 

 expansions of some kind ; these some- 

 times constitute large frills on the sides 

 of the neck. The eyes are always fur- 

 nished with lids, which can be completely 

 closed ; the ears are freely exposed, and 

 the tongue is short and thick, and free 

 only at the tip. ]\Iany of the species are 

 of the most brilliant green color, but they 

 suddenly change this gay painting on 

 being alarmed, and become of more 

 sobi'r coloring; some of them, under 

 these circumstances become completely 

 black. 

 Genus IGUANA : If/uana. — This includes the Common Iguana, /. tuhcrculata, which may be 

 regarded as the type of the family ; it is a large lizard, which attains a length of four or five feet, 

 and is common in all the tropical parts of America. It is of a greenish color, mottled with a 

 brighter green, and banded with brown on the tail ; along the back runs a comb-like crest, and 

 the throat is furnished with a large membraneous expansion, which is also denticulated in front. 

 This reptile is much sought after in the countries where it abounds, its flesh being regarded as 

 a great delicacy, although it is said not to be particularly wholesome. It passes a great part of 

 its existence in trees, and is commonly taken Avhen resting on a branch, by slipping a noose over 

 its head, its captor Avhistling to it while engaged in the operation. Its teeth have the crowns 

 compressed and serrated, and it lives principally upon fruits and seeds. It is said to take the 

 water freely, and to swim with facility. 



Oenus BASILISCUS : Basiliscus. — The Basilisk, B. Amcricavus, although perfectly harm- 

 less, is certainly one of the most hideous of reptiles in its appearance. It is found in South 

 America, and occasionally attains a length of upward of three feet. Instead of the comb-like 

 dorsal ridge of the Iguana, it is furnished with a broad membrane running down the back, and 

 a second, still broader, on the upper surface of the tail, and these are supported by a series of 

 bones, consisting of the elongated spinous processes of the dorsal and caudal vertebrte, and having 

 the appearance of long perpendicular fins. 



THE COMMON IGUANA. 



THE AGAMID^. 



These seem to take the place of the Iguanas in the Old World. They are principally inhabitants 

 of the warmer regions of Asia and Australia, and the intervening islands ; a few are found in the 

 south of Australia, Van Diemen's Land, and New Zealand, and a few others in Africa, from 

 Egypt to the Cape of Good Hope. One remarkable genus is f<jund in the United States. In 

 their general form, and in the character of their peculiar appendages, they closely resemble the 

 American Iguanas ; but some of them are particularly remarkable. One of these is the Chlariiy- 

 dosaurus Kingii., which is not uncommon in the neighborhood of Port Essington. The appear- 

 ance of this lizard is most extraordinary ; it is furnished with a curious crenated membrane, 

 forming a sort of frill or tippet round its neck, and covering its shoulders. Each side of this 

 singular appendage is furnished with four cartilaginous plates, by means of which it can be folded 



