57 
so large a pouch under the throat, (which is 
quite wanting in the other sex,) that it has been 
separated as a genus under the name of Sitana. 
The Common Stellio (Lac. Stellio ), which 
was formerly much esteemed for its medical 
qualities, has bands of large spines round its 
tail. The Trapeli or Mutable Agamse, so 
called, from the rapidity with which they change 
the colour of their skin, are mostly armed with 
irregular spine-like scales, as the Cape Agama 
(Trapelus hispidus ), the Yellow-striped Agama 
(Agama atra), and the Mutable Agama (Agama 
ruder ata). 
The Earless Agamae (Phrynocephalus) have 
the same irregular scales as the Mutable Agamse, 
but they differ from them all, by their ears being 
hid under the skin, as in the Chameleons ; one 
of the eared Phrynocephali (Phrynocephalus 
auritus) has the margin of the lips produced 
and fringed, and the claws very long, differing 
in that respect from the others, as Pallas’s 
Phrynocephalus (Lacerta caudivolvula ), and the 
Ocellated Phrynocephalus (Agama ocellata'). 
The Dragons (Draco') differ from all these by 
the skin of the sides being extended into the 
form of wings, and supported 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 the creature leaps from branch to branch 
they are expanded, and act as a parachute; 
there 
room x. 
