LIZARDS. 31 



herbivorous, but others subsist on insects. Of the true Iguanas, such 

 as Iguana tuMrcidata (381, fig- ?»2), the flesh is often eaten; the 

 species grows to between 5 and G feet. Polychrus (402) has the 

 chamaeleon-like power of changing its colour. Many species, notably 

 the partially aquatic Basfdisciis (387), have spines or fin-like ex- 

 pansions running down the middle line of the back ; and in the 

 so-called Calif ornian Toad {Phrynosoma rornutum, 398, fig- 33) and 

 its relatives the whole body is spiny. The last-named Lizards have 

 the peculiar power of squirting jets of a red fluid supposed to be 

 blood from their eyes. In their depressed form and spine-clad skin, 

 these Lizards present a curious parallelism to the Moloch Lizard in 

 the Agamidce. It will be noticed that in the more typical Iguanas, 



Fig. 33. 



Spiny Iguana, or Oalifornian Toad {Phrynosoma cornutum). (No. 396-) 



which are arboreal in their habits, the body and tail are much com- 

 pressed, and the prevailing colour is green, to harmonise with the 

 foliage among which these reptiles dwell. The Sea-Iguana {Amhly- 

 rhynchus cristatus, 389), of the Galapagos Islands, spends much of its 

 time in the sea, and feeds on sea-weed. It is represented on land by 

 the nearly allied Conolophus subcristatus (403)- Examples of other 

 genera, such as the Fijian Brarhylophiis (398) and the short-tailed 

 Hoplocercus (401) of Brazil, are also shown. 



The two families Zonuridce- (426-428) and Xenosauridce serve to Case 20. 

 connect the Ifiuanidce, with the Anguidm. In both the dentition is 

 pleurodont, but the teeth are solid only in the Xenosauridce. In 

 that family the anterior part of the tongue is retractile (as in the 

 Anguidce), and bony nodules are developed in the skin of the body. 

 On the other hand, the Zonuridce. have short non-retractile tongues 

 like those of the Iguanida;., but bony nodules are developed at least 

 in the skin of the head, where they roof over the temporal region. 

 The second family is represented only by a single species from South 



