[AN^-ALS X. Y. Academy of Sciences, Vol. XX, Xo, 4, Paet II, pp. 239-242. 



26 October, 1910] 



NEW SPECIES OF FOSSILS FEOM THE THAYNES LIME- 

 STONE OF UTAH^ 



By George H. Girty 



{Presented by title before the Academy, 3 October, 1910) 



The few species described below are from the rocks in the Wasatch 

 Mountains of Utah, which were discriminated by the geologists of the 

 Fortieth Parallel Survey nnder the title "Permo-Carboniferous." At 

 the same time, Meek, in describing AvicuUpecten occidaneus, a species 

 which is abundant in and characteristic of the "Permo-Carboniferous," 

 cites the horizon as the "Upper Coal Measures Limestone," a series which 

 occurs below the "Permo-Carboniferous" and in which A. occidaneus is 

 not found at all. 



As a result of more detailed study of the "Permo-Carboniferous" in 

 the Park City district of the Wasatch Mountains, Mr. J. M. Boutwell 

 found occasion to divide the series into three formations, which he named 

 from below upwards, the Woodside, the Thaynes and the Ankareh. From 

 the typical Woodside, which is a red shale formation, no fossils are 

 known. The Thaynes, consisting of thin muddy limestones and earthy 

 beds, has furnished an extensive molluscan fauna, chiefly characterized 

 by a great diversity of pectinoid species which may belong to several 

 genera. Of these a few have already been described, AvicuUpecten utaJi- 

 ensis, A. weherensis, A. curticardinalis, A. parvula, A. occidaneus, to- 

 gether with SedgwicTcia concava, Myacites inconspicuus and the shells 

 probably wrongly identified as Myalina aviculoides and M. permiana. 

 All of these species occur in the Thaynes and were probably originally 

 described from that formation. The Ankareh has proved scantily fossil- 

 iferous in the typical area, but the fauna so far as known is closely 

 related to that of the Thaynes. 



The "Permo-Carboniferous," however, is not confined to the area of 

 the Wasatch Mountains, but it outcrops through central Utah and is 

 foimd again in the Grand Canyon region, where it constitutes the Per- 

 mian of Walcott's Kanab Canyon section. There is yet no reason to 

 believe that Walcott's Permian is not essentially the same in its limits as 

 the "Permo-Carboniferous" and that it does not contain beds equivalent 

 to the AVoodside, the Thaynes and the Ankareh. 



'^ Published by permission of the Itirector of the [United States Geological Survey. 



(239) 



