IGUANIDA. 175 



AGAMA, Daudin. 



The Agamee bear a great resemblance to the common Stellios, particularly 

 in their inflated head ; but the scales of their tail, which are imbricate and not 

 verticillate, distinguish them from that genus. Their maxillary teeth are 

 nearly similar, and there are none in the palate. This genus is also divided 

 into various subgenera. 



ISTIURUS, Cuvier. 



The distinguishing character of this genus consists in an elevated and 

 trenchant crest, which extends along a part of the tail, and which is supported 

 by high spinous apophyses of the vertebne ; this crest is scaly like the rest of 

 the body ; the scales on the belly and tail are small, and approach somewhat 

 to a square form ; the teeth are strong, compressed, and without denticula- 

 tions : there are none in the palate : there is a series of femoral pores. The 

 skin of the throat is smooth and lax, but without forming a dewlap. 



DRACO, Linnaeus*. 



The Dragons are distinguished at the first glance, from all other Saurians, 

 by their first six false ribs, which, instead of encircling the abdomen, extend 

 outwards in a straight line, and support a production of the skin, forming a 

 kind of wing that may be compared to that of a bat, but which is not con- 

 nected with the four feet ; it acts like a parachute in supporting them, when 

 they leap from one branch to another, but has not sufficient power to enable 

 them to rise like a bird. They are small animals, completely invested with 

 little imbricated scales, of which those on the tail and limbs are carinated. 

 Their tongue is fleshy, but slightly extensible, and somewhat emarginate. 

 A long pointed dewlap hangs under their throat. All the known species are 

 from the East Indies. 



It is perhaps to this tribe of agamians, that we should approximate a very 

 extraordinary reptile, which is only to be found among the fossils of the old 

 Jura limestone formation. 



PTERODACTYLUS, Cuvier. 



It had a short tail, an extremely long neck, and a very large head ; the jaws 

 armed with equal and pointed teeth ; but its chief character consisted in the 

 excessive elongation of the second toe of the fore-foot, which was more than 

 double the length of the trunk, and most probably served to support some 

 membrane which enabled the animal to fly, like that upheld by the ribs of the 

 dragon. 



* The term fyuxav, draco, generally designated a large serpent ; Dragons, with a crest 

 or beard, are spoken of by ancient writers, a description which can only apply to the 

 Iguana ; Lucian is the first who mentions Flying Dragons, alluding, no doubt, to the 

 pretended Flying Serpents treated of by Herodotus. St. Augustine, and other subsequent 

 authors, ever after described Dragons as having wings. 



