276 REPTILIA. 



tained by long spinous vertebral apophyses ; this crest is scaly like the rest of tlte body ; the belly and 

 caudal scales are small, and approach a little to a square form ; the teeth are strong, compressed, and 

 undenticulated, and are found only on the jaws ; there ai-e femoral pores, and the skin of the throat is 

 lax, without forming an appendage. 



The Dragons {Draco, Lin.) — 

 Are known at the first glance from all other Saurians, by their first six false ribs, instead of encircling 

 the abdomen, being extended in a straight line, so as to support a production of the skin, which forms 

 a sort of wing, and acts as a parachute when the animal leaps from bough to bough. They are small- 

 sized reptiles, everywhere covered with minute imbricated scales, those of the tail and limbs being 

 keeled. Their tongue is fleshy, but slightly notched and little extensible. Beneath the throat is a 

 long pointed [inflatable] appendage, sustained by the hyoid bone, and laterally by two other small 

 bones. The tail is long ; the thighs have no pores ; and there is a slight dentelation on the neck. 

 Each jaw has four small incisors, flanked by a long and pointed canine, behind which are a dozen 

 triangular and trilobate molars. 



Tliey have, therefore, the scales and throat-appendag'e of the Iguanas, with the head and teeth of the Stellions. 

 All the known species are from the East Indies. 



Siiana, Cuv., differs in the non-prolongation of the ribs, and by having an enormous throat-appendage, which 

 reaches to the middle of the belly, and is more than double the height of the animal. 



It is perhaps to this tribe of Agamas that we should approximate a most extraordinary fossil 

 reptile, the remains of which are imbedded in the Jm-a limestone, — 



The Pterodactylus, Cuv. 



It had a very short tail, a very long neck, and very large head ; the jaws armed with even and 



pointed teeth ; but its principal character consisted in the excessive elongation of the second toe of its 



fore-feet,which extended twice the length of the trunk, and probably [undoubtedly] served to sustain some 



membrane by which the animal was enabled to fly, similar to that which the ribs of the Dragon support. 



The second section of the family of Iguanas, or that of the Iguanas proper, is distinguished 

 from the preceding by the existence of palatal teeth. 



The Iguanas, properly so called, {Iguana, Cuv.) — 

 Have the body and tail covered with small imbricated scales ; a range of spines along the back, or of 

 raised, compressed, and pointed scales, and under the throat a compressed and pointed appendage, the 

 edge of which is sustained by a cartilaginous production of the hyoid bone. The thighs have the same 

 range of porous tubercles as in the Lizards proper, and their head is covered with plates ; each jaw is 

 surrounded by a range of triangular, compressed teeth, with denticulated edges ; and there are also 

 two little ranges at the back of the palate. 



/V species common in all tropical America (Lac. iguana, Lin.), which grov/s to four or five feet in length, is 

 esteemed very fine eating, though hurtful in syphilitic disorders. It lives chiefly upon trees, occasionally enters 

 the water, and subsists on fruit, grain, and leaves. The female deposits eggs in the sand as large as those of a 

 Pigeon, which are agreeable to the taste, and almost without white. Several others inhabit the same countries. 



Ophryessa, Boie. 



Small imbricated scales, a slightly projecting dorsal crest prolonged over the compressed tail, palatal 



teeth, and denticulated maxillary teeth which approximate it to the Iguanas, but no throat-appendage 



no"- femoral pores. 



The Basilisks {Basilisctis, Daud.) 



No femoral pores, but palatal teeth as in the last ; the body covered with small scales ; and a 



continuous elevated crest along the back and tail, which supports spinous vertebral apophyses as in 



the tail of Istiurus. 



The Marblets {Polychrus, Cuv.) — 



Have palatal teeth, and femoral pores, like the Iguanas, but which are inconspicuous : their body, 



however, clad with small scales, is not crested ; the head is covered with plates; tail long and sharper. 



edged ; the throat extensile, forming an appendage at the will of the animal ; and they change colour 



like the Chameleons, having a very voluminous lung, which fills nearly the whole body, and subdivides 



into numerous branches ; their false ribs also surround the abdomen, as in the Chameleons, and unite 



to form complete circles. 



