INTRODUCTION. 



This second volume contains an account of the families Iguanidce, 

 Xenosauridce, Zomiridce, An(/uid(e, Auniellidce, Helodermatidce, Va- 

 ranidce, Xantusiidce, Teiida;, and AmpJiisbcenidce ; it is therefore 

 chiefly devoted to American Lizards. 



The increase in the number of species known, and of species and 



specimens represented in the British Museum, since the publication 



of the general works by Dumeril and Bibron and by Gray is shown 



in the following tables : — 



Number of Species characterized 



Families. by Dum. & Bibr. by Gray. in present volume. 



Iguanidae 94 126 293 



Xenosauridae — — 1 



Zonuridae 6 8 14 



Anguidae 17 25 44 



Anniellidae — — 2 



Helodermatidae .... 1 1 3 



Varanida3 12 23 27 



Xantusiidae — — 4 



TeiidEe 29 44 108 



Amphisbacnidae 15 15 65 



Total.. 174 242 501 



VOL. II. 6 



