588 ZOOLOGY BATRACHIANS AND REPTILES OF ARIZONA. 



so fertile in reptilian life. But the present article is believed to be a fair 

 resume of the subject as at present understood. To render it more generally 

 available, and useful as a work of reference, a copious bibliography has 

 been prepared, representing a large proportion of extant references, and a 

 nearly complete synonymy. Descriptions of lately published or less gen- 

 erally known species are given in many cases, together with such critical 

 and field notes as the author found himself in position to offer. 



The classification adopted is that of the eminent herpetologist, Professor 

 Cope, whose nomenclature is followed in the main, though a different stand 

 is taken in some instances ; and the identifications of species are mainly 

 upon the same authority, the author's work being little more in this instance 

 than that of a compiler. 



The most striking feature of the batrachian fauna of Arizona is the pov- 

 erty of this region in Urodela (one species), which bear small proportion, 

 in numbers of species or of individuals, to the Anura (eight species), in 

 comparison with the ratio existing between these two groups in most parts 

 of the United States ; while the Anura themselves are poorly represented. 

 This is probably due in greatest part to the dryness of the region as a 

 whole. The Ckelonia (four or five species) are likewise poorly represented, 

 for the same reason. On the other hand, the region is rich in Opliidia 

 (thirty-four species), including a larger proportion of venomous species than 

 any other district of the United States ; and it is still richer in number of 

 individuals and of species of Saitria (thirty-six species). No other portion 

 of our country exhibits such a preponderance of these forms of animal life. 



NOTE. 



Since the present paper was set in metal, a few addenda have come to my 

 knowledge, being indicated as Arizonan in the preceding article by Dr. Yarrow. Such 

 are Phrynosoma blainvillii, Sceloporus tristiclius (sp. n.J, 8. spinosus, Chilopoma rvfo- 

 punctatum (g. s. n.J, Pityophis sayi mexicanus, Diadophis piilcJiellus, Opkibolus doliatus 

 annulatus, Bufo lentiginosus cognatus, B. punctatits. But the close connection of the 

 two memoirs renders their omission of less consequence. 



November 15, 1875. 



