CHAPTER IV. 



The collections of Batrachians and Reptiles upon which this report is 

 based were made in the years 1871, 1872, 1873, and 1874, by the different 

 naturalists of the expedition in California, Arizona, Nevada, New Mexico, 

 Utah, and Colorado. 



But a small number of new species has been discovered, but many 

 secured of great rarity and value, and of much interest as increasing* our 

 knowledge of the geographical distribution of the reptilian fauna of West- 

 ern North America. 



The collection of 1871 was made principally in Arizona and Nevada 

 by Mr. F. Bischofif, with the assistance of Dr. W. J. Hoffman and others of 

 the party. Owing to Mr. Bischoff's sudden disappearance in Chicago, and 

 the loss of his note books by fire, it is impossible to give more than a mere 

 list of his specimens, which may possibly prove of interest as chronicling 

 the occurrence of some species very rare and valuable. 



The collection of 1872, while it embraces but five new species, is par- 

 ticularly rich in numbers, and affords good types of the characteristic 

 reptiles of the localities visited. 



It is a matter of some interest, as an established fact, that, as birds 

 Were found to be more numerous in the proximity of settlements, the same 

 is true of serpents ; very few, except the Crotalus, being found upon the 

 barren plains, although occasionally an individual was encountered strag- 

 gling along apparently in pursuit of food, or a more desirable dwelling place. 

 The neighborhood of Provo and Utah Lake afforded nearly all the species 

 enumerated in the list, and an almost entire absence of venomous serpents 

 was noted at this place, although on the " benches ", at the base of the Wali- 

 satch Mountains, the Crotalus is met with sparingly. The beautiful Eutauia 

 vagrans, rightly called from its wide range, is exceedingly abundant, and 

 PityopMs sayi var. bellotia equally so. Bascanium var. flaviventre, called 



r.u 



