BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 3, pp. 395-412 July 15, 1892 



JURA AND TRIAS AT TAYLORVILLE, CALIFORNIA. 



BY ALPHEUS HYATT. 



{Rend before the Society December 29, 1891.) 

 ( !< )NTENTS. 



Page 



Introduction 39o 



The Trias ■ 397 



I >iscovery 397 



Swearinger Slates 397 



Monotis Bed 397 



Daonella Bed 397 



Rliabdoceras Bed ' 398 



Halobia Bed 399 



Hosselkus Limestone 399 



< reneral Remarks 400 



The Jura 401 



Lower Jura or Lias (Hardgrave Sandstone) 401 



Middle Jura or Oolite 403 



Thompson Limestone (Opis Bed) 403 



Mormon Sandstone (Sphseroceras Bed) 40:! 



Tnoceramus Bed 4().i 



[Tpper Jura or Malm 400 



Bicknell Sandstone I Trigonia Bed) 406 



Bicknell Tuff 407 



Hinchman Tuff (Stylina Bed) 407 



General Remarks 409 



Tabular View '. 412 



I NTRODUCTION. 



The results given in this paper are preliminary, bu1 it will be seen 

 by those familiar with such researches thai my opinions, although for 

 obvious reasons here considered as provisional and therefore subject to 

 revision in final publications, have been based upon abundanl materials. 

 These consist of four different collections: The first was made by Mr. 

 I. C. Russell ami by the author and his son in the summer of L 888, and 



I.I V Hi i i. .., i , \m.. Voi„ :;. I II '" ,| 



