THE IGUANOID LIZARDS 2493 



to gather this the basilisks are astir with the first rays of dawn, while during the 

 heat of the day they prefer to rest among the most leafy boughs. At the slightest 

 sound, they raise the head, inflate the throat, and elevate the crest, and as soon as 

 the bright, yellow-irised eye detects the presence of a foe, the basilisks throw them- 

 selves instantaneously into the water above which they are usually reposing. In 

 swimming, the head and neck are raised, the fore-limbs serve the part of propellers, 

 while the crested tail acts as a rudder; hence the common name of " ferrymen" is 

 applied to these lizards. At the end of April or beginning of May the female lays 

 from twelve to eighteen eggs in some cranny at the foot of a tree, where they are 

 left for the sun to hatch. 



Nearly allied to the basilisks are the three species of ridge-headed 



lizards (Corythophanes) of Central America, characterized by the head 

 Lizards 



being prolonged backward into a bony, helmet-like projection, while 



the tail is devoid of a crest, although the neck and back are provided with a low 

 appendage of this nature. On the throat there is both a pouch and a transverse fold. 

 The most interesting of the three species is the one named C. hernandezi, in which 

 the head is crowned with a helmet-like prolongation so like that of the chamaeleon 

 that the creature is commonly spoken of under that name by the Mexicans. L,ike 

 the anolis lizards, these reptiles are in the constant habit of changing their some- 

 what sombre colors, and it has been observed in a captive specimen that whereas 

 the patch on the pouch was white during the day, at night it assumed, like the 

 other light parts of the body, a blackish hue. 



While agreeing with the basilisks in having the plates on the 

 s under surface of the toes distinctly keeled, there are a number of 

 genera in the family distinguished by the absence of any backward prolongation 

 of the crown of the head. Among these we select for mention the stilted lizards, 

 specially characterized by the large size of the occipital shield of the head, the 

 presence of a vacuity in the breastbone, the small or moderate-sized scales of the 

 tail, the long and highly-curved toes, and the presence of tusk-like teeth in the 

 jaws. There are but two representatives of the genus, both of which have a 

 wide distribution in South America. The figured species (Uraniscodon umbra}, 

 which attains a length of about a foot, two-thirds of which are occupied by the 

 long and cylindrical tail, has a short and frog-like head, raised into curved ridges 

 over the eyes, with the muzzle very blunt, and the lower jaw longer than the 

 upper. The skin of the neck is curiously puckered inferiorly, the folds forming 

 a pair of pouches on the sides, although there is no pouch on the throat. In 

 form, the body is at most but slightly compressed, with, a low and slightly-serrated 

 crest running from the nape down to the back; and the uniform scales of the 

 back are small and overlapping, and those on the top of the head enlarged. The 

 long and bent toes are markedly compressed, and are furnished with short but 

 strong claws. In coloration this species is one of the handsomest of its tribe. The 

 general ground color of the upper parts is reddish or purplish brown, ornamented 

 with more or less distinctly defined blackish transverse bars; a broad black band 

 traverses the fold in front of the shoulder, and may extend across the nape; while 

 frequently in front of this band there is a large yellowish-orange spot on each side 



