252 THE CAMBRIAN. [bull. 81. 



OCOEE. 



This name was proposed by Prof. J. M. Safford in 1856 for a series of 

 conglomerates and slates that he considered to be superjacent to the 

 Mica-slate group and subjacent to the Chilhowee sandstone. 1 



PROSPECT. 



For the lower members of the Cambrian section, in the Eureka dis- 

 trict, Nevada, Mr. Arnold Hague proposed, in 1881, Prospect Mountain 

 quartzite and Prospect Mountain limestone. 2 As now known the up- 

 per portion of the Prospect Mountain quartzite is characterized by the 

 Olcnellus or Lower Cambrian fauna, and the Prospect Mountain lime- 

 stone by the Middle Cambrian fauna of the Rocky Mountain section. 



EASTERN AND WESTERN SANDSTONE. 



These names were applied to the horizontal, evenly bedded sand- 

 stones of the south shore of Lake Superior, east and west of Keweenaw 

 Point, by Dr. B. D. Irving in 1883 as convenient terms under which to 

 describe the character of the sandstone and its geographic distribu- 

 tion. 3 



LAKE SUPERIOR SANDSTONE. 



Dr. J. J. Bigsby described the red and white sandstone along the 

 south shore of Lake Superior as early as 1825, and in the account of 

 the geology of Lake Superior by Capt. H. W. Bayfield, he speaks of 

 the sandstones of Lake Superior. 4 As used by Capt. Bayfield, the Lake 

 Superior sandstone included both the Cambrian sandstones of the south 

 shore, and the pre-Cambrian sandstones of Keweenaw Point and the 

 north shore of the Lake. It has been used by various authors in the 

 same general manner, and has little value as a term in stratigraphic 

 geology. 



POTSDAMIC. 



Prof. C. H. Hitchcock proposed in 1888 for the rocks 5 containing the 

 Cambrian fauna, the name Potsdamic or Taconic. 



1 A geological reconnaissance of Tennessee ; first biennial report. Nashville, 1856, p. 151. 

 *U.S.Geol. Survey, Second Ann. Rep., 1880-'81, 1882, p. 27; 3d Ann. Rep., p. 254. 



3 The copper-bearing rocks of Lake Superior. U. S. Geol. Survey, Monograph, vol. 5 ; 1883, pp. 351, 365. 



4 Outlines of the Geology of Lake Superior. Quebec Lit. and Hist. Soc. Trans., vol. 1, 1829, pp. 15-22. 

 6 Date of the publication of the report upon the Geology of Vermont. Boston Soc. Nat. Hist. Proa 



vol. 24, 1888, p. 37. 



