40 
ROOM X. 
Nat. Hist. 
side, and not thrown off, a new tail often springs out 
of the crack, so that the member becomes forked. A 
specimen of a Lizard with such a tail, may be seen in 
this Case. 
Cases 3 and 4 contain those Saurian Reptiles which 
have short contractile tongues, slightly notched at the 
end. 
The first of these are the Iguanas, which have their 
teeth attached to the inner edge of the jaw-bone, and 
mostly lobed and indented. They are all found in 
America. 
Some of the Guanas have a compressed dewlap 
under the throat, and the back crested; among which 
are the common Guana ( Iguana tuber culata ), w r hich is 
used both for food and medicine in the West Indies, 
and the banded Guana {Iguana fas data). 
Other species of this genus have only a fold across 
the throat, as the Spiny-tailed Guana ( Iguana acan- 
thura ), Clouded Guana ( Iguana nubila ), Sword-tailed 
Ophyessa ( Ophyessa superdliosa ), Umber Ophyessa 
(O*'plica), Collared Tropidurus (Tropidurus tor - 
quatus ), Keeled Leiocephalus ( Leiocephalus carina - 
tus ), Northern Tropidolepis ( Tropidolepis undula - 
tus ), Collared Tropidolepis (T. torquatus ), Doug¬ 
lass’s Toad-Lizard ( Phrynosoma Douglassii ), and 
Blainville’s Toad-Lizard (P. Blainmllii ). These 
animals are very quarrelsome, and fight with great 
ardour when they meet. 
In other species of Guanas, the ribs surround the 
body like those of the Chameleon, and like them, these 
animals have the faculty of changing their colour with 
great rapidity. Three of the genera belonging to this 
division of the Guanas are each marked with very 
striking characters; the first, the Basilisk ( Basilis- 
cus ) 9 has a compressed hood on the back of the head, 
and a fin-shaped crest down the back; the second, 
(Chamczleopsis) , from Mexico, has a compressed ridge 
on the back of the head, but only a slight dorsal crest. 
Both these have simple toes. The third, ( Anolis ), 
has 
