34 NATURAL HISTORY. [UPPER FLOOR. 
head armed with spines over the back of the ears, and the 
scales large and directed upwards ( Calotes), which latter lay 
fusiform eggs. The Bronchoceles differ from the Calotes , 
by the scales of the back being small and horizontal; and 
the Acanthosaura has a square head and long subulate 
spines over the eyes. The true Agamee ( Agama ) have 
often bundles of spines on the sides of the neck. The male 
Sitana has a large pouch under the throat, (which is quite 
wanting in the female,) and they have no hinder thumb. 
The Stellio, which was formerly much esteemed for its sup¬ 
posed medicinal qualities, has bands of large spines round 
its tail. The Trapeli or Mutable Agamse, so called from the 
quickness with which they change the colour of their skin, 
are generally armed with irregular, spine-like scales. The 
Earless Agamae (Phrynocephali) have the same irregular 
scales as the Mutable Agamae, but they differ from them, 
and all the former, by the drum of their ears being hidden 
under the skin, as in the Chameleons. The Megalochilus 
differs from the former in the margin of the lips being 
spread out and fringed, and the claws very long. The 
Dragons ( Dracones ) differ from all these by the skin of 
the sides being spread out into the form of wings, and 
held up by the end of the ribs. The wings, when the 
animal is at rest, are folded together on the sides of the 
body, but when it leaps from branch to branch they are 
spread out, and act as a parachute; there are several spe¬ 
cies, differing from each other in the length of the throat- 
pouches, and in the colour of the wings. The rest of the 
Agamidce are furnished with a series of minute glands on 
the under side of the hind legs; as the Gemmatophorce, pe¬ 
culiar to New Holland, which have rough scales like the 
Mutable Lizards, and the Lophyri have a crest of large 
scales on the back, which has caused them to be confound¬ 
ed with the Basilisks. Others with these glands, are pe¬ 
culiar for having the tail surrounded with rings of scales. 
In Uromastyx, the scales of the tail are large and spinous; 
in Leiolepis they are small and smooth. 
The family of Chameleons ( Chameleonidce , Case 4) 
have been long celebrated on account of the rapidity with 
which they change their colour; but most of the other 
Saurian Reptiles have the same faculty, and many in as 
great a degree. They are remarkable for the great dis- 
