M. F. Sumichrast on the Habits of some Mexican Reptiles. 500 



finding upon it, during the hot hours of the day, a Basilisk 

 acting the part of a sentinel. With his body voluptuously ex- 

 tended, as if to absorb as much as possible of the solar heat, he 

 remains in a state of perfect quietness ; but if some noise attracts 

 his attention, he raises his head, inflates his throat, and rapidly 

 agitates the membranous crest with which his occiput is crowned. 

 His piercing eye, with its dull-yellow iris spangled with gold, 

 glances inquisitively on every side; if the danger be imminent, 

 his body, previously flaccid and soft, draws together like a spring, 

 and, leaping with the rapidity of lightning, he throws himself 

 into the water. In swimming, he raises the head and breast ; 

 his fore feet strike the water as oars, whilst his long tail furrows 

 it like a rudder. From this habit the animal has received its 

 name of Pasarios {passe-ruisseaux), which is also applied, al- 

 though erroneously, to a species of an allied genus, Corythophanes 



At the end of April or the beginning of May, the female 

 deposits from twelve to eighteen eggs in a hole at the base of a 

 stump or trunk of a tree, where she leaves them to be hatched 

 by the heat of the sun. These eggs, which in form and colour 

 are identical with those of the Iguanas, measure four-fifths of an 

 inch in their long diameter, and about half an inch in their 

 shorter. The young reptiles which issue from them in the 

 course of a few days are very difi'erent from the adults in their 

 colours. 



The food of the Basilisk consists essentially of insects, which 

 it captures with much dexterity when they settle upon the low 

 branches overhanging the brooks, near the spot where it is on 

 the watch. 



Age and sex induce some modifications in the colour of dif- 

 ferent individuals. The occipital membrane and the tail, which 

 in the females and young are of an olive-yellow colour, are 

 tinted with a fine blood-red in the old males. 



Genus Corythophanes, Boie. 



Corythophanes chamceieopsis, Dum. 



Chamaleopsis Hernandezii, Gray. 

 ChamcEleo mexicanus, Hernandez. 



If the kind of osseous casque which characterizes this reptile 

 were not of a very difi'erent nature from that which adorns the 

 head of the Basilisk, one would be tempted, at the first glance, 

 to refer the Corythophanes to the same genus as the latter, so 

 much do they resemble each other in the form of the body. 

 But in the Basilisk the occipital prominence only consists of a 

 membranous hood, supported internally by a greatly developed 



Ann. ^ Maff. N. Hist. Ser. 3. Vol. xiii. 33 



