LOCALITIES. 167 



4j. Middle Cambrian: Limestone at the head of Deep Creek, Canyon quadrangle (U. S. G. S.), Yellowstone 

 National Park, Wyo. 

 Billingsella plicatella. 



Eoorthia sp. ^ 



*Huenella abnormis. 



The first and third of these fossils may not have been collected from the same bed. 



4k (4i is limestone interbedded in these shales; see 4g, 4h, and 4p). Middle Cambrian: About 725 feet (221 m.) 

 above the base of the Cambrian, in the shales of the Gallatin formation of Peale [1893, PI. IV], on the north 

 side of West Gallatin (Gallatin) River, northeast of Logan, Threeforks quadrangle (U. S. G. S.), Gallatin 

 County, Mont. (C. D. Walcott, 1898). 

 Obolus (Westonia) ella. 



41. (For stratigraphic position and association, see pp. 140 and 158.) Lower Cambrian: Limestone in the equiv- 

 alent of the Pioche formation at Pioche and in the House Range [Walcott, 1908a, p. 11], on a ridge 2.5 

 miles (4 km.) northwest of the town of Cherry Creek, White Pine County, Nev. (O. H. Hershey). 



Micromitra (Iphidella) pannula. 



Acrotreta claytoni. 



Acrotreta primaeva. 



4m (about 175 feet below 4n). Middle Cambrian: Sandstones about 150 feet (45.7 m.) above the unconformable 

 base of the Cambrian, in the divide at the head of Jackson Creek (locally known as Sheep Creek), a creek 

 flowing into Jackson Lake about 0.5 mile (0.8 km.) south of its northwestern corner, Teton Mountains, 

 Grand Teton quadrangle (U. S. G. S.), Uinta County, Wyo. (C. D. Walcott, 1898). 

 Obolus tetonensis. 



4n (about 175 feet above 4m). Middle Cambrian: Limestone about 325 feet (99.1 m.) above the unconformable 

 base of the Cambrian, in divide at the head of Jackson Creek (locally known as Sheep Creek), a creek flowing 

 into Jackson Lake about 0.5 mile (0.8 km.) south of its northwestern corner, Teton Mountains, Grand Teton 

 quadrangle (U. S. G. S.), Uinta County, Wyo. (C. D. Walcott and F. B. Weeks, 1898). 

 Micromitra pealei. [ Lingulella helena. 



Obolus (Westonia) ella, j Acrotreta attenuata. 



M. pealei also occurs in locality 4n',, which is probably a slightly different bed at the locality given for 4n. 



4o (about 50 feet above 4n). Middle Cambrian: Shale about 375 feet (115 m.) above the unconformable base of 

 the Cambrian, in divide at the head of Jackson Creek (locally known as Sheep Creek), a creek flowing into 

 Jackson Lake about 0.5 mile (0.8 km.) south of its northwestern corner, Teton Mountains, Grand Teton 

 quadrangle (U. S. G. S.), Uinta County, Wyo. (C. D. Walcott, 1898). 

 Acrotreta definita. 



4p (see 4g, 4h, and 4k). Middle Cambrian: About 225 feet (68.6 m.) above the base of the Cambrian, in lime- 

 stones interbedded in the Flathead shales of Peale [1893, p. 21], on the north side of West Gallatin (Gal- ' 

 latin) River, 2 miles (3.2 km.) northeast of Logan, Threeforks quadrangle (U. S. G. S.), Gallatin County, 

 Mont. (C. D. Walcott, 1898). 

 Micromitra pealei. 



4c[ (115 feet above 4v; see 3j and 4v). Middle Cambrian: About 315 feet (96 m.) above the unconformable base 

 of the Cambrian and 190 feet (57.9 m.) above the top of the quartzitic sandstones, in a shale which corre- 

 sponds in position to the upper part of shale No. 6 of the Dearborn River section [see Walcott, 1908f, p. 

 202], on the ridge between Gordon and Youngs creeks, about halfway between Gordon Mountain and Car- 

 dinal Peak, Ovando quadrangle (U. S. G. S.), Powell County, Mont. (C. D. Walcott, 1905). 



Ptychoparia 3 sp. 



Bathyuriscus productus (Hall and Whitfield). 

 Zacanthoides. 



*Micromitra (Iphidella) nyssa 

 Micromitra (Iphidella) pannula. 

 *Acrothele colleni. 

 Wimanella simplex. 



4ct' (just below 4q; see 3j, 4q, and 4v). Middle Cambrian: Limestone about 310 feet (94.5 m.) above the uncon- 

 formable base of the Cambrian and 185 feet (56.4 m.) above the top of the quartzitic sandstones, in a shale 

 which corresponds in position to the upper part of shale No. 6 of the Dearborn River section [see Walcott, 

 1908f, p. 202], on the ridge between Gordon and Youngs creeks, about halfway between Gordon Mountain 

 and Cardinal Peak, Ovando quadrangle (U. S. G. S.), Powell County, Mont. (C. D. Walcott, 1905). 



Micromitra (Iphidella) pannula. 



Obolus (Westonia) ella. 



4r. Upper Cambrian: Just above the Middle Cambrian, in the limestones of the Gallatin formation of Peale 

 [1893, PL IV], on a ridge 8 miles (12.8 km.) east of Yellowstone River and 3 miles (4.8 km.) north- 

 northeast of Mount Delano, Livingston quadrangle (U. S. G. S.), Park County, Mont. (C. D. Walcott, 1898). 

 Eoorthis remnicha. 



