210 CAMBEIAN BRACHIOPODA. 



68p (same horizon as 58k). (For stratigraphic position and association, see p. 129.) Lower Cambrian: Drift 

 block of limestone believed to have come from the limestone forming 1 of the Mount 'Whyte formation 

 [Walcott, 1908c, p. 240 (9)], found near the Canadian Pacific Railway track just west of the tunnel, 3 miles 

 (4.8 km.) east of Field, British Columbia, Canada (C. D. Walcott and L. D. Burling, 1907). 



Nisusia alberta var. I Hyolithes billingsi Walcott. 



Nisusia (Jamesella) lowi. I Ptychoparia. 



58r. (For stratigraphic position and association, seep. 127.) Middle Cambrian: About 1,800 feet (548.6 m.) above 

 the Lower Cambrian and 3,200 feet (975.4 m.) below the Upper Cambrian, in the limestones forming 2 of 

 the Stephen formation [Walcott, 1908f, p. 211], in the amphitheater between Mounts Stephen and Dennis, 

 above Field on the Canadian Pacific Railway, British Columbia, Canada (C. D. Walcott and L. D. Burling, 

 1907). 



Ptychoparia. 



Neolenus serratus (Rominger). 



Ogygopsis klotzi (Rominger). 



Obolus mcconnelli. 

 Acrotreta depressa. 

 Hyolithellus annulatus (Matthew). 



58s (=57r). (For stratigraphic position and association, see p. 129.) Lower Cambrian: About 150 feet (46 m.) 

 below the Middle Cambrian, near the base of the limestones forming 3 of the Mount Whyte formation [Wal- 

 cott, 1908c, p. 241 (10)], just above the tunnel on the north shoulder of Mount Stephen, about 3 miles 

 (4.8 km.) east of Field, British Columbia, Canada (C. D. Walcott and L. D. Burling, 1907). 



Micromitra (Paterina) labradorica var. I Acrotreta sagittalis taconica. 



Micromitra (Iphidella) pannula. I Ptychoparia 3 sp. 



58t, (For stratigraphic position and association, see p. 129.) Lower Cambrian: Sandy shale about 150 feet (45.7 m.) 

 below the Middle Cambrian, just below the big cliff on the east shoulder of Castle Mountain, north of the 

 Canadian Pacific Railway, Alberta, Canada (L. D. Burling and Stuart Walcott, 1907). 

 Obolus parvus. 



S8w. (For stratigraphic position and association, seep. 127.) Middle Cambrian: About 1,300 feet (396 m.) above 

 the Lower Cambrian, in the shales of the Stephen formation [Walcott, 1908a, p. 3], northeast slope of Castle 

 J, Mountain, facing the amphitheater north of the Canadian Pacific Railway, Alberta, Canada (C. D. Wal- 



cott and L. D. Burling, 1907). 

 Obolus mcconnelli. 



58z. (For stratigraphic position and association, seep. 128.) Middle Cambrian: About 1,875 feet (572 m.) above 

 the Lower Cambrian and 3,100 feet (945 m.) below the Upper Cambrian, in the limestone forming 2b of the 

 Stephen formation [Walcott, 1908f, p. 211], on Mount Bosworth, north of the Canadian Pacific Railway 

 between Hector and Stephen, on the Continental Divide between British Columbia and Alberta, Canada' 

 (C. D. Walcott and L. D. Burling, 1907). 



Micromitra zenobia. Ptychoparia. 



Nisusia alberta var. Neolenus. 



Menocephalus. 



59. (For stratigraphic position and association, see p. 140.) Middle Cambrian: Limestone at the base of the western 

 •slope of Combs Peak, near the plain of Antelope Valley, Eureka district [Hague, 1892, Atlas], Eureka County, 

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

 Lingulella arguta. I Agnostus tumidosus Hall and Whitfield. 



Acrotreta attenuata. | Dorypyge ? quadriceps (Hall and Whitfield). 



59f. (For stratigraphic position and association, seep. 152.) Middle Cambrian: Limestones immediately under- 

 lying the Spence shale member of the Ute limestone [M^alcott, 1908a, p. 8], in a saddle north of the creek 

 which flows into Mill Canyon from the west, about 5 miles (8 km.) west-southwest of Liberty and 15 miles 

 (24.2 km.) west of Montpelier, Bear Lake County, Idaho (C. D. Walcott, jr., and L. D. Burling, 1907). 



Micromitra (Iphidella) pannula 

 Lingulella desiderata. 

 Acrotreta pyxidicula, 

 Solenopleura sp. 

 Neolenus sp. 



Anomocare sp. 

 Ptychoparia sp. 

 Agraulos sp. 

 Stenotheca sp. 

 Zacanthoides sp. 



(For stratigraphic position and association, see p. 151.) Middle Cambrian: Limestones immediately over- 

 lying the Spence shale member of the Ute limestone [Walcott, 1908a, p. 8], in a saddle north of the creek 

 which flows into Mill Canyon from the west, about 5 miles (8 km.) west-southwest of Liberty and 15 miles 

 (24.2 km.) west of Liberty, Bear Lake County, Idaho (C. D. Walcott, jr., and L. D. Burling, 1907). 



Lingulella sp. 

 Acrothele subsidua. 

 Acrotreta cf. idahoensis. 

 Ptychoparia 3 sp. 



Neolenus. 



Microdiscus. 



Zacanthoides idahoensis Walcott. 



Menocephalus. 



