PREFACE 



The present work may be regarded as, in one sense, a 

 second edition of an earlier volume, entitled "The Reptiles 

 of the Pacific Coast and Great Basin." At the time that 

 publication was issued, knowledge of the reptiles of the 

 western United States was very limited and had nowhere 

 been brought together in such a way as to be readily avail- 

 able. The earlier work was originally written as a herpe- 

 tology of California, but, before publication, was enlarged 

 to include, also, the reptiles of Oregon, Washington, Idaho 

 and Nevada. 



The years which have past since this earlier work was 

 published have added greatly to our knowledge. Partly 

 on this account and partly because a large portion of the 

 original edition was destroyed in the San Francisco con- 

 flagration of 1906, it seems desirable to bring out a new 

 volume covering much the same field. In doing so it has 

 been thought best to enlarge the scope of the work by 

 extending the geographical limits to include Arizona, Utah, 

 Sonora, Lower California, the islands in the Gulf of 

 California, and the Revilla Gigedos. 



Thus it will be seen that, while the present work is based 

 upon the former one, it has been so much enlarged by the 

 addition of other material as to considerably change its 

 character. It is hoped that this will add to its usefulness. 



The following new names are proposed: Dipsosaurus 

 carmenensis, Dipsosaurus catalmensls^ Sauromalus sieving 

 and Ufa slevini. 



The illustrations have been made from original photo- 

 graphs taken by the author. With few exceptions, stated on 



