272 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 



description of De Verneuil, which have the angular terminations of. the cardinal area. Also 

 some young specimens from Iowa in my collections* show distinctly roiuided cardinal angles. 



Associated with that species are Productus JiaUanus and Rhynchonellas of the Pugnax 

 type (B. acuminata) , which distinctly belong to this fauna as developed in America. 



As I have reported in other places, this Pugnax pugnus fauna occurs in the New York 

 section, both in Ithaca and High Point zones, which are both above the representative of the 

 Cuboides zone (TuUy limestone) of that region, and before the appearance there of the typical 

 Spirifer disjunctus fauna. But in New York the species which dominates in the Iowa, Arizona, 

 and Russian faunas (Spirifer hungerfordi and Spirijier anossqfi) is entirely absent, or certainly 

 very rare even if eventually it should be discovered. From this and other similar peculiarities 

 presented by the New York faunas, I am inclined to think that the horizon at which the Pugnax 

 fauna enters the New York sections is later chronologically than that of the formations holding 

 the fauna in Russia, and possibly also appreciably later than the zone marked by it in Iowa 

 and Arizona. 



Although Spirifer whitneyi presents many characters of the general Spirifer disjunctus 

 type, its range in the Russian and also in the west Em-opean Devonian confirms this same 

 view. The Arizona fauna does not present any very close affinity with the distinctly Chemung 

 {Spirifer disjunctus) fauna of New York. 



This earlier age for the Spirifer hungerfordi fauna is also indicated by the development 

 of Productus. All the representatives of that genus reported from Arizona and from the same 

 fauna as expressed in Iowa indicate an earlier stage of its development than that exhibited 

 by the Productellas of the Chemung formation of New York. 



From these and other considerations it seems reasonable to adopt Tschernyschew's view 

 that the zone in Russia containing the anossq^, fauna is the equivalent of the Stringocephalus 

 zone of western Europe as well as of the Hamilton formation of North America; and therefore 

 that the fauna is properly a Mesodevonian rather than Neodevonian faima. On these grounds 

 we should place the formation bearing this fauna in Arizona in the Mesodevonian, although 

 its representatives do not appear in the New York fauna until the opening of Neodevonian 

 time. 



The stratigraphic relations of the limestones at Globe and Bisbee exhibit 

 a hiatus' from Cambrian to Devonian but the strata are apparently conformable 

 throughout to the close of the Carboniferous. 



In the Clifton-Morenci district Lindgren '*^ found a formation, the Morenci, 

 which consists of 75 feet of compact fine-grained argillaceous limestone below and 

 100 feet of clay shale above. The strata are conformable to the Ordovician and 

 Carboniferous. They have yielded a meager fauna, which indicates a Devonian 

 horizon, though it might be Silurian or Carboniferous. 



I 12. ARIZONA. 



Reagan ^^^ states in regard to the Devonian of the Fort Apache region, in 

 Arizona : 



Immediately overlying the Silurian on the periphery are alternating chert and flint strata 

 followed by massive, very fossiliferous light-colored fine-grained marble limestone, which in 

 turn is followed by a grit. This formation, like the Silurian, is exposed as a narrow strip 

 encircling the ElUson dome from the Nantan Mountains on the southeast around by the north- 

 east to the Tonto Basin, where it forms one of the "rim" series of that basin. The strip thus 

 formed is sometimes more than 3 miles wide, though it is usually much less. Besides this 

 belted strip several of the buttes of the Tonto region belong to this formation, one of which 

 is situated 3 miles northeast of Ellison. This butte is called Juniper Butte on the Government 



