INTRODUCTION. 
Tus second volume contains an account of the families Iguanide, 
Xenosauride, Zonuride, Anguide, Anniellide, Helodermatide, Va- 
ranide, Xantusiide, Tetide, and Amphisbenide; 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 Duméril and Bibron and by Gray is shown 
in the following tables :— 
Number of Species characterized 
Families. by Dum. & Bibr. by Gray. in present volume. 
Iguanide .......... 94 126 293 
Xenosauride ...... — — 1 
Zonuride .......... 6 8 14 
Anguide .......... 17 25 44 
Anniellide ........ — — 2 
Helodermatide 1 1 3 
Varanide.......... 12 23 27 
Xantusiide ........ — — 4 
Telide ............ 29 44 108 
Amphisbeenide...... 15 15 65 
Total.. 174 242 561 
VoL, II. b 
