122 SAURIA. 



Archipelago than on the continent, but they have not yet been found in Ceylon. The 

 character by which they are at once recognized is the peculiar additional apparatus for loco- 

 motion formed by the much-prolonged five or six hind ribs, which are connected by a broad 

 expansible fold of the skin, the whole forming a subsemicircular wing on each side of the 

 body. The Snakes are the only order in the whole animal kingdom in which the ribs serve 

 as organs of locomotion ; but whilst in that order all the ribs are charged with a function 

 for which no other organ exists, in the Dragons only a part of the ribs are modified for the 

 purpose of assisting four well developed limbs. The Dragons are Tree Lizards, and, jumping 

 from branch to branch, they are supported in the air by their expanded parachutes, which 

 are laid backwards at the sides of the animal while it is sitting or merely running. If 

 the hind extremities of a Dragon were cut off, it would lie helpless on the ground ; but it 

 would still move with great velocity if it were merely deprived of its wings. The locomotion 

 of the Dragons is a series of leaps, and not a continuous running : they are the Anoles of 

 the Old World. 



The species are extremely similar to one another, scarcely diflFering in size, and one general 

 description will suffice for all. The head is thick and high, with a short, obtuse snout, 

 covered with very small scales; the labial shields are low, varying in number*. The tongue 

 is elongate-cylindrical, attached to the gullet in its whole length, not or but slightly notched 

 in front. Two of the front teeth in the upper and lower jaws are larger than the rest. 

 The nostrils are small, round, situated in a single, small, rather prominent shield: the 

 direction in which they pierce this shield is of great importance for the distinction of the 

 species. In some the nostrils are visible when the head is viewed from above {Dracocella), 

 in others only from the side. The eye is of moderate size, with well developed eyelids, 

 and with a round pupil, the Dragons being diurnal lizards delighting to bask in the sun. 

 The tympanum is present in all species ; but whilst it is naked and exposed in some, it is 

 covered with small scales in others (Dracimculus) ; this difierence also offers an important 

 character for the distinction of the species, but less so than the nostril, as young examples of 

 a species which usually has a scaly tympanum, sometimes show the centre of this membrane 

 scaleless, whereby naturalists may be misled in their determinations. 



The skinny appendages of the throat are merely folds of the skin, ornamental and sexual, 

 like the wattles of the throat of gallinaceous birds ; they have no ca\ity in their interior, 

 and have no communication with the cavity of the mouth or with the respiratory organs. 

 They are supported by the posterior horns of the hyoid bone, and can be erected or spread 

 out when the animal is excited. Such appendages as those in the Dragons always betray 

 an excitable temper. They are found in both sexes, one in the middle and one on each 

 side of the throat ; but they are much more developed in the mature male, where the middle 

 gular appendage sometimes attains to a length thrice as great as that of the head. Most of 

 the species have a short, low crest, formed by granular or triangular scales, along the middle 

 of the neck, which also is more developed in the adult male than in the female and young, 

 if present at all in a species. This nuchal crest is generally accompanied by small isolated 

 or serial tubercles on the hind part of the head or on the side of the neck. 



* In comparing the dorsal scales with the labial shields, in the specific descriptions, I have always taken 

 the labials of middle size. 



