INTRODUCTION. XIII 



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 Iguanidce 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 llayti, 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. 

 Iguana, 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 weather extended along leafless 

 branches of trees. They are hunted with dogs, and taken from the tree 



