INTRODUCTION, XIIL 
Dragons or flying lizards, Draco. These possess a membranous expansion 
on each side of the body, supported by the posterior or false ribs, which are 
much lengthened for the purpose. This membrane may be folded back 
against the body or expanded to serve as a parachute, as in case of the 
flying squirrel. The ordinary mode of progression is by means of short 
jumps. A dermal expansion or goitre depends from the throat; it is dis- 
tended when in use by the hyoid apparatus. The tail is long and slender. 
All the species of Dragons are small; the total length seldom exceeds seven 
or eight inches. Lyriocephalus has its ears hidden under the skin, and its 
snout surmounted by a globular prominence. — Ceratophora has a lobe or 
conical pointed horn above the tip of the snout. Moloch, an Australian 
lizard, literally bristles with spines. Chlamydosaurus, also Australian, has 
broad fan-like membranes extending backward from the sides of the back 
of the head. 
The Iquanide belong almost entirely to the new world. They are diurnal. 
Their eyelids are valvular, and their tongues thick and slightly notched. 
This is one of the families in which forms and habits are most diversified, 
as will be seen by the instances cited below. It contains some of the largest 
species of the order. Among these are the terrestrial cactus-eating Cono- 
lophus and the amphibious Amblyrhynchus, which feeds on sea weeds and 
when pursued secretes itself beneath the rocks under the water, genera 
inhabiting only the Galapagos Archipelago. Metapoceros, the Navassa lizard, 
found also in Hayti, is very large and strong. To aid in burrowing, older 
specimens have peculiar scrapers under the basal joints of the third and 
fourth toes, and the second joint of the third toe of the hind feet. These 
scrapers are on the front side of the toes as they are pushed backward; they 
are merely expanded and solidified scales, the lower extremities of which 
form a sharp serrated edge of five or more denticulations arranged in a 
curve, convex forward In Thysanodactylus the scales along the sides of the 
toes are so much expanded as to answer the purpose of a web in swimming. 
Iquana, though venturing north into Mexico, is properly a South American 
genus. It is also a common lizard in the West Indies. The species are 
large, rivaling the Galapagos lizards in bulk but much longer. Their 
flesh and eggs are much prized by the natives of the localities in which 
they are found. Where they have not been disturbed they are very tame 
and enjoy sunning themselves in pleasant w sather extended along leafless 
branches of trees. They are hunted with dogs, and taken from the tree 
