398 REPTILIA ORDER IILSQUAMATA. 



lobes running along the two sides of the tail, and likewise on the hinder 

 borders of the legs. The toes also are completely connected by web-like dila- 

 tions, the first in each limb being clawless. A peculiarly marked type of 

 coloration further aids in the recognition of this species. The countries 

 bordering the Mediterranean are the chief habitat of another genus known as 

 Tarentola, of which the common wall-gecko is the most familiar representa- 

 tive, all the species having the toes moderately dilated, but only the third 

 and fourth clawed. The genus ranges as far south as the west coast of Africa, 

 and is likewise represented by a species from the West Indian Islands. 

 Whereas a large number of geckos frequent trees, walls, or buildings, some 



are found in open sandy districts, and 

 these latter naturally have feet of ordinary 

 type, as adhesive discs would be useless. 

 In countries where these lizards abound, 

 almost every house is tenanted by at least 

 a pair. When undisturbed, such denizens 

 will scamper over the walls with the 

 greatest speed in search of flies, uttering 

 Fig. 11. FRINGED GECKO (Ptychozoum). now and then their shrill cries. It is, 



doubtless, owing to these vocal powers 



that geckos are so dreaded by the uneducated in all parts of the world an 

 analagous instance of the inspiration of a similar dread bejng afforded by the 

 death-watch insects. 



A second family of geckos (Eublepharida), of which there are only three 

 genera, differ from the foregoing in being furnished with eyelids, and also in 

 having cup-and-ball joints to the backbone. 



The third family of the sub-order includes the three species of the Mala- 

 gasy genus Uroplates, and is termed the Uroplatidce. While resembling the true 

 geckos in the doubly-cupped vertebrae, as well as in many 

 Scale-footed other structural features, these lizards agree with the follow- 

 Lizards. ing nine families in that the inner ends of the collar-bones 

 Family lack the loop-shaped expansion characteristic of the geckos. 

 PyrjopodidcE. The next family is that of the scale-footed lizards, or Pygopo- 

 did<z, which are confined to Australia, and appear to present 

 a considerable resemblance to the Geckonidce, with which they agree in the 

 general conformation of the skull. All these lizards have assumed a snake- 

 like form of body, with the complete loss of all external vestiges of the front 

 limbs, although the hinder pair are represented by two large, flap-like scaly 

 expansions, without any sign of division into toes externally. The commonest 

 species grows to a length of about twenty inches, and is coppery-grey in 

 colour, sometimes having three or five rows of blackish spots or streaks. 



A very large proportion of the lizards of the eastern and southern countries 



of the Eastern Hemisphere pertain to the very extensive and important family 



of the Agamidce, a family which includes at least a couple 



Family of hundred species ranged under thirty distinct generic 



Agamidce. groups. These lizards have a tongue of the same type as 



that of the geckos, no dilation of the inner extremities of 



the collar-bones, and no bony plates beneath the overlapping scales with 



which the head and body are invested ; but they differ from all the foregoing 



groups in their acrodont dentition. The eyes, which are relatively smaller 



than in the geckos, are furnished with movable eyelids, and have circular 



pupils. Small scales cover the crown of the head, and the scales on the lower 



