LIZARDS 69 



are occasionally not averse to quite young birds, and small 

 rodents. 



Metopocerus, which is closely allied to the true Iguana, 

 is represented by a single species, M. cornutus, the Horned 

 Iguana, which is characterized by a large, conical, horn-like 

 scale on the snout. A dorsal crest and gular appendage 

 are present, as in Iguana, but less developed. It is also 

 principally vegetarian, and specially partial to oranges. 



The Ctenosaurs, genus Ctenosaura, may be distinguished 

 from the latter two genera by their cylindrical tails, which 

 are conspicuously armed with spiny scales, forming 

 whorls. 



The Black Ctenosaur, C. acanthura, of California and 

 Mexico, is frequently seen in menageries. In this species 

 the dorsal crest is continuous with the caudal, and the 

 tail, which is moderately long, is covered above with 

 alternate rings of large spines and small, smooth scales. 

 The colour of this lizard is usually entirely black, sometimes 

 dark brown or olive, with blackish markings forming cross 

 bands on the body and nings on the tail. The young are 

 green. 



Although a ground lizard, the Black Ctenosaur makes 

 its home in the forest, laying its eggs in the holes which 

 it digs at the foot of trees. It feeds on mice, young birds, 

 and earthworms, varying its diet with fruit. Although 

 when first captured it is usually very savage, dealing out 

 blows with its spiny tail and attempting to bite, it soon 

 becomes tame, taking food from the hand. 



The Spiny-tailed Ctenosaur, C. erythromelas, of 

 Mexico, is the New World analogue of the Old World 

 Mastigure, the tail of this animal being short, depressed, 



