86 REPTILES AND BATRACHIANS 



teeth are inserted almost on the parapet of the jaws, while 

 in others they are attached more distinctly to the inner 

 side, the dentition in many cases being exactly intermediate 

 between the acrodont and the pleurodont. 



These lizards show great variation in form and scaling : 

 some have a Monitor-like appearance, and are arboreal, 

 others are strictly terrestrial, and more like typical lizards, 

 while in a few cases the limbs have become rudimentary, 

 such forms approaching in general appearance the burrow- 

 ing Amphisbaenids. 



The Common Teguexin, Tupinambis teguexin, inhabit- 

 ing the forest districts of Trinidad and tropical South 

 America, from the Guianas to Uruguay, attains a length 

 of nearly four feet. Its very large head, covered with 

 symmetrical shields, is scarcely distinct from the neck, the 

 latter measuring up to seven inches in circumference. 

 The cheeks of the animal are provided with large pouches, 

 which are much inflated when the lizard becomes angry. 

 The tail is long and rounded and made use of as a weapon 

 of defence, as in the Monitors. The ground colour is 

 olive brown above, marbled or transversely barred with 

 black, and with a series of more or less distinct rows 

 of lighter spots ; the under-surface is yellowish with 

 transverse bands. 



The Red Teguexin, T. rujescens, which is confined to 

 the Argentine, is very similar to T. teguexin^ but with all 

 the scales very much smaller. The coloration is reddish 

 above, with brown transverse bands ; the lower parts with 

 more less distinct irregular transverse dark spots. The 

 largest specimen recorded, one at present living in our 

 Zoological Gardens, measures three and a half feet in length. 



