M.F.Sumichrast on the Habits of some Mexican Reptiles. 505 
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 
chameleopsis. 
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 different 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, Boié. 
Corythophanes chameleopsis, Dum. 
Chameleopsis Hernandezii, Gray. 
Chameleo mexicanus, Hernandez. 
If the kind of osseous casque which characterizes this reptile 
were not of a very different 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. & Mag. N. Hist. Ser. 3. Vol. xin. 33 
