CROCODILIANS, LIZARDS, AND SNAKES. 217 



SUnua, which hicks the outer toe, pontadactyle. The chivicle is not dilated, and 

 the interchivicle is T-shaped or anchor-shaped, frequently small; the sternum usu- 

 ally presents two fontanelles, which however, are missing in lAjHoceplialus and 

 Moloch, the latter genus being especially remarkable for having the sternum divided 

 longitudinally. 



The tympanum is either exposed or concealed under the skin. The eye is small 

 and the pupil round ; eyelids well developed. The tongue is thick, entirely attached 

 or slightly free in front, not, or but slightly, nicked anteriorly; it is more free, pro- 

 tractile, and more distinctly incised in the herbivorous genera Lophura, TAolepia, 

 and Uromasilx. 



Femoral and pricanal pores are absent in the majority of the genera; it is a remark- 

 able fact that they exist, at least in the males, in all Australian genera but one 

 {Clielosania, known .as yet from a unique specimen), whereas they are missing in 

 all others except Uromastix and Liolepis. There are no sjaumetrical plates on the 

 head or on the belly ; and ornamental appendages, such as crests, gular pouches, etc., 

 are frequently present, either in the males only or in both sexes. The tail is usually 

 long and not fragile; it is prehensile only in the genus Cophotis, and some Fhrynoce- 

 phall have the curious faculty of curling upward the extremity of that organ. 



Fig. 15. 

 AoAMm^. Liolepis bellii Gray. 



The digits are usually keeled inferiorly or denticulated laterally. The shape of the 

 body as well as the scaling vary considerably, according to the genera, and in 

 adaptation to the modes of life. Generally speaking, ground Agamoids have the 

 body depressed, and arboreal compressed, but a division of the genera into terres- 

 trial and arboreal, which has hitherto been almost generally accepted, must be given 

 up as impracticable and unnatural. Most Agamoids are exclusively insectivorous; 

 Lophura, Liolepis, and rromastix are herbi- or frugivorous, while some species of 

 Jgama have a mixed diet ; again, a systematic division into insectivorous and herbiv- 

 orous, as has been proposed by Theobald, would be as unsatisfactory as that into 

 terrestrial and arboreal. 



Leaving out the strongly specialized genera Draco and Moloch, all the forms pass 

 very gradually one into another in different directions, rendering a sharp generic 

 division, and, still more, a serial arrangement, a matter of great difficulty. 



The Agamidio inhabit Africa, Asia, Australia, and Polynesia. They are most 

 numerous in species as well as in genera in the Indian region. In Africa they are 

 represented by only three genera, viz, Agama, AporosccUs, and in the northern parts, 

 Uromastix. Four species extend slightly beyond the limits of Asia and Africa 

 into southeastern Europe. They are absent from Madagascar and New Zealand. — 

 Boulenger. 



