ZONURID^. 107 



New World. The Holaspidce is also founded on one species only, 

 the Holaspis Guentheri, which again is supposed to be South 

 American. It has four well- developed limbs, a double row of 

 plates along the back and upper surface of the tail, and the latter 

 organ is curiously serrated laterally. 



The Zonuridce, constitute a considerable family, to which some 

 eighteen or twenty genera are assigned, and w^hich present con- 

 siderable modification of form. The ears are distinct, whereas in 

 the Chalcidce they are hidden under the skin. The head is 

 pyramidal, or depressed, and covered with regular many-sided 

 shields ; eyes with two valvular lids. Limbs mostly well developed, 

 but short in some, and rudimentary, or even wanting in the so- 

 called " Glass- snakes " which constitvite the sub- family Pseudo- 

 podince. There is no external trace of them in the North American 

 Griass-snake, Ophisaurus tentralis ; and in the Old World genus, 

 Pseudopus, there is only one pair, posterior, rudimentary, and 

 undivided. These reptiles are long, and serpentiform in shape : 

 whilst in other Saurians the whole skin of the belly and of the 

 sides is extensible, the extensibility is limited in the " Glass- 

 snakes " to a separate part of the skin ; and, as Dr. Giinther 

 remarks, " the scaly covering of the upper and lower parts is so 

 tight that it does not admit of the same extension as in Snakes 

 and other Lizards ; and the Pseudopus, therefore, could not receive 

 the same quantity of food in its stomach as those animals, were 

 it not for the expansible fold of the skin running along each side 

 of its trunk." One species of Pseudopus, the P. Pallasii, inhabits 

 Asia Minor and the south-east of Europe; and there is another, 

 P. gracilis, in the Indo-Chinese countries (or those lying eastward 

 of the Bay of Bengal). A second sub-family, Gerrlwiiotiyice, is 

 peculiar to America, and consists of more ordinarilj^-shaped Lizards, 

 which are ranged in four g-enera. Together with the OpJnsaiirus, 

 or American Glass-snake, they are the only known Zonuridm that 

 inhabit the New World. The great mass of this family and all of 

 its most characteristic species are African, and these are arranged 

 by Dr. Gray under the sub-families CicignincB and Zonurinm. In 

 the first of these sub-families the tail is smooth, or unarmed, and 

 in the second it is spinous. The Cordules, Cordylus, Zonurus, &c., 

 are very characteristic Lizards chiefly of Southern Africa, several 



