CHAPTER V. 



INTRODUCTORY. 



This article rests primarily upon the collections and observations made 

 by the writer in Arizona in 186465. These collections, containing many 

 new species, were placed, together with the author's field notes, in the hands 

 of Prof. E. D. Cope, by whom the new species were described in a paper 

 'published in the Proceedings of the Philadelphia Academy for 1866. Special 

 reference is made to this paper, which contained, furthermore, the identifica- 

 tion of the species, forty-four in number, contained in the collections, with 

 some of the author's field notes, critical observations of Professor Cope's, 

 and an enumeration of the additional species then known to inhabit the 

 Territory, sixty-eight in number. 



The present paper was drawn up some years since to form part of a 

 General Work upon the Natural History of Arizona, which the author then 

 contemplated, but which pressure of other engagements compelled him to 

 abandon. During the time it has lain in manuscript, it has been retouched 

 at intervals, with the addition of various matter, until it has assumed the 

 present shape of a synopsis of the species now known to inhabit the Terri- 

 tory, eighty-three in number (exclusive of numerous subspecies). 



The aim has been to include none which have not actually been found 

 in Arizona as at present bounded. It will be remembered that the present 

 Territory includes the western half of what was formerly New Mexico, 

 together with a considerable part of Sonora, obtained by what is known as 

 the "Gradsden purchase"; consequently, many species described from 

 "New Mexico" and "Sonora" are really Arizonan. 



Doubtless some species already known to inhabit this Territory have 

 not come to the writer's knowledge as such, but it is believed that these are 

 very few ; and, no doubt, also species remain to be discovered in this region, 



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