FLYING LIZARD. 549 



abdominal scuta, by way of feet. The cervical 

 ribs of the Cobra de Capello, or hooded snake of 

 the East Indies, are employed for the mecha- 

 nical purpose of supporting an expansion of the 

 skin of the neck, which forms a kind of hood, 

 capable of being raised or depressed at the plea- 

 sure of the animal.* These ribs are entirely 

 unconnected with the respiration of the serpent. 



In the Draco volans, which was to be fur- 

 nished with instruments for assisting it in its 

 distant leaps through the air, it is again the ribs 

 which are resorted to for furnishing the basis of 

 such an apparatus. On each side of the dorsal 

 vertebrae, as is seen in the skeleton of this animal 

 (Fig. 222), the eight posterior ribs on each side, 

 instead of having the usual curvature inwards, 

 and instead of being continued round to encircle 

 the body, are extended outwards and elongated, 

 and are covered with a thin cuticle, derived from 

 the common integuments. The ordinary muscles 

 which move the ribs still remain, but with 

 greatly increased power, and serve to flap these 

 strangely formed wings at the pleasure of the 

 animal, during its short aerial excursions. 



Among the mammalia we meet with a few 

 species, which have a broad membrane, formed 

 of a duplicature of the skin, extended like a 

 cloak from the fore to the hind extremities, and 



* Phil. Trans, for 1804, p. 346. 



