iv PREFACE 



Handling the entire class — the crocodilians, turtles 

 and tortoises, lizards and snakes of both the New and 

 the Old World — elaborate description is necessarily lim- 

 ited to groups,, and says little of individual species. The 

 method here has been to select representative types, 

 treating them according to their importance as to ana- 

 tomical characteristics and habits. The North American 

 reptiles have, however, received considerable attention, 

 as they naturally attract our special interest, while their 

 habits and structure must be compared with their Old 

 World allies, if a general idea of the Class Reptilia is 

 to be acquired. But among the illustrations the South 

 American and the Old World reptiles predominate, for 

 here is a field quite neglected from a photographic stand- 

 point, and demanding much space. Thus, to make room 

 for the great array of foreign reptiles, the illustrations 

 of the North American species have been limited to a 

 condensed but representative series. To thoroughly 

 round up the subject the author has prepared detailed 

 charts showing the classification and approximate num- 

 ber of species among all the genera of reptiles found 

 in all parts of the world. Such will impress upon the 

 student the full scope of the subject, though references 

 to numerous genera in the text must be omitted. 



The author may be permitted to say, without being 

 accused of immodesty, that, however the text of this 

 volume may be received, its illustrations make it of high 

 value, and indeed unique among books on the same sub- 

 ject. The plates from photographs taken from life 

 will be useful to the student and interesting to the gen- 

 eral reader. They are not merely pictures "snapped" 

 at the most convenient moment, but life studies from 

 poses displaying distinguishing characteristics, and in- 

 volving work on many of the negatives requiring the 



