574 C. SCHUCHERT PALEOGEOGRAPHY OF NORTH AMERICA 



Near the base of the Hueco, Girty records Triticites, Productus cora r 

 Marginifera cf. wdbasliensis, Squamularia perplexa, Spirifer rockymon- 

 tanus. It will be seen that these forms are suggestive of those of the 

 higher Pottsvillian. In higher beds at different horizons, Girty 214 col- 

 lected among other forms Fusulina elongata, ScTiwagerina ?, Lithostro- 

 tion, Chwtetes milliporaceus, Ortliotlietina, Enteletes, Camaroplioria, re- 

 lated to European forms ; Pugnax, Productus, related to Ural and Aubrey 

 forms; Spirifer cf. marcoui, Hustedia, Composita mexicana, Omphalo- 

 trochus obtusispira, etcetera. 



The Aubrey extends to within 25 miles of Moab, Utah, yet its fauna is 

 very different from that of the Hermosa of the Mississippian sea. The- 

 writer believes that the Aubrey faunas are younger than those of the Her- 

 mosa, but still Pennsylvania and of a distinct faunal province — that is,., 

 of the western or Cordilleran basin. The Aubrey limestone on Kanab 

 creek attains a depth of 820 feet, while the underlying Aubrey sandstones,, 

 with gypsum, along the Grand Canyon reach about 1,000 feet. 215 



In the Grand Canyon region the Aubrey is followed by the Shinumo 

 sandstone, 250 feet in thickness. It appears to be a dune sandstone for- 

 mation. Above this is the Sublime limestone and calcareous sandstone 

 about 600 feet in thickness, near the middle of which, in a zone 200 feet 

 thick, occurs the fauna described by Newberry. This is the Productus 

 ivesi fauna, and includes Archceocidaris longispina, Meekella Occident '.alts,. 

 M. pyramidalis, Productus ivesi (the guide fossil), P. nodosus, P. occi- 

 dentalism Aviculopecten Colorado ensis, and Allorisma capax. There are 

 many other species, not one of which is familiar when compared with the- 

 eastern Missourian forms. In Utah are found Chonetes utahensis, Pro- 

 ductus semistriatus, P. multistriatus , Spirifer scooina, S. earner atus occi- 

 dentalism and Spiriferina pulclira. The Embar formation of central Wyo- 

 ming also displays the S. pulclira fauna. The Embar limestone, Girty 216 

 says, "has a very different fauna from the Kansas Permian, but it may be 

 equivalent to it, or even later. The fauna is not related to the Guadalu- 

 pian. It occurs in Utah just below the Permo-Carboniferous, and is 

 known also in Idaho and Nevada/' 



In a very recent paper Girty 217 states : 



"The Mississippian faunas, together with the earlier Pennsylvanian ones,, 

 appear to be absent [in the Trans-Pecos region]. The Hueconian fauna is 

 widely distributed over the West, ranging indeed into Alaska, while it is even 



214 Girty in Richardson : Bull. no. 9, University of Texas Mining Survey, 1904. 



215 Spurr : Bull. no. 208, U. S. Geological Survey, 1903. 



218 Girty in Darton : Bull. Geological Society of America, vol. 19, 1908, p. 418. 

 217 Girty : Journal of Geology, 1909, p. 311. 



