228 CAMBKIAN BRACHIOPODA. 



186. Upper Cambrian: Sandy layers above the massive Potsdam sandstone 0.5 mile (0.8 km.) southeast of 

 Redwood, Jefferson County, N. Y. (C. D. Walcott, 1886). 

 Lingulella (Lingulepis) acuminata. 



185a. Upper Cambrian: Sandy layers 20 feet (6 m.) above the massive Potsdam sandstone, east side of Indian 

 View, 3 miles (4.8 km.) south of Theresa, Jefferson County, N. Y. (C. D. Walcott, 1886). 

 Lingulella (Lingulepis) acuminata. 



185z. (For stratigraphic position and association, seep. 148.) Lower Ordovician: Limestones at the base of the 

 Lower Ordovician [Walcott, 1908f, p. 191], in Blacksmith Pork Canyon, about 9 miles (14.4 km.) east of 

 Hyrum, Cache County, Utah (C. D. Walcott and L. D. Burling, 1906). 



Obolus discoideus. 

 Eoorthis desmopleura. 

 Sjmtrophia nundina. 



Orthoceras. 

 Endoceras. 

 Fragments of trilobites. 



186. Lower Ordovician: Near line of contact between red and gray Ordovician limestone, in red siliceous lime- 

 stone about 30 feet (9.1 m.) above the pre-Cambrian rocks, Williams Canyon, Manitou, El Paso County, 

 Colo. (C. D. Walcott, 1890). 



Eoorthis desmopleura nympha. 

 Syntrophia nundina. 



Lingulella desiderata. 

 Schizambon manitouensis. 

 Eoorthis desmopleura. 



186a (slightly higher horizon than 186). Lower Ordovician: Near line of contact between red and gray Ordovician 

 limestone, in siliceous red limestone about 3.5 feet (10.7 m.) above the pre-Cambrian rocks, Williams Canyon, 

 Manitou, El Paso County, Colo. (T. W Stanton, 1890). 

 *Schizambon manitouensis. 

 Eoorthis desmopleura. 

 Syntrophia nundina. 



187. Lower Ordovician: Red siliceous limestone 105 to 122 feet (32 to 36. 7 m.) above the pre-Cambrian rocks, 

 2 miles (3.2 km.) below Manitou Park Hotel, El Paso County, Colo. (Whitman Cross, 1882). 

 Lingulella desiderata. 

 Eoorthis desmopleura. 



201. (For stratigraphic position and association, see p. 139.) Passage beds between the Upper Cambrian and the 

 Ordovician: Arenaceous Pogonip limestone on east slope of ridge east of Hamburg Ridge Eureka district 

 [Hague, 1892, Atlas], Eureka County, Nev. (Arnold Hague and C. D. Walcott, 1880). 

 *Lingulella pogonipensis. 

 Acrotreta idahoensis alta. 

 .Eoorthis hamburgensis. 



201a. (For stratigraphic position and association, see p. 139.) Lower Ordovician: Pogonip limestone, east slope 

 of the ridge east of Hamburg Ridge, Eureka district [Hague, 1892, Atlas], Eureka County, Nev. (C. D. 

 Walcott, 1882). i 



*Obolus (Westonia) iphis. 

 Lingulella pogonipensis. 

 *Schizambon typicalis. 

 Acrothele sp. 



Acrotreta idahoensis. 



Eoorthis hamburgensis. 



Syntrophia nundina. 



Agnostus prolongus Hall and Whitfield. 



202. (For stratigraphic position and association, see p. 139.) Lower Ordovician: Pogonip limestone on the summit 

 of the ridge directly southeast of the Jackson mine, northwest of Shadow Canyon, Eureka district [Hague, 

 1892, Atlas], Eureka County, Nev. (C. D. Walcott, 1880). 



Lingulella manticula. I Elkania ambigua. 



Lingulella sp. I Acrotreta idahoensis. 



203. (For stratigraphic position and association, see p. 139.) Lower Ordovician: Pogonip limestone on spur of 

 Hamburg Ridge extending out southwest from Wood Cone, Eureka district [Hague, 1892, Atlas], Eureka 

 County, Nev. (C. D. Walcott, 1880). 



Syntrophia nundina. 

 Bathyurus congeneris Walcott. 

 Bathyurus tuberculatus Walcott. 



203a. (For stratigraphic position and association, see p. 139.) Passage beds between the Upper Cambrian and 

 the Ordovician: Limestones at base of Pogonip limestone in the spur of Hamburg Ridge extending out 

 southwest from Wood Cone, Eureka district [Hague, 1892, Atlas], Eureka County, Nev. (C. D. Walcott, 1880). 

 Lingulella pogonipensis. 

 *Acrotreta curvata. 

 Agnostus tumidosus Hall and Whitfield. 



