402 CAMBRIAN BEACHIOPODA. 



(88b) "St. Croix sandstone' ' along the railroad track near Taylors Falls, Chisago County; (339d) "St. Croix sand- 

 stone' ' at Taylors Falls, Chisago County; (339f) "St. Croix sandstone" near Minneiska (Miniska) on Mississippi Kiver 

 near the line between Wabasha and Winona counties; (97b) "St. Croix sandstone" below the gi-een-sand bed and 

 25 feet (7.6 m.) above St. Croix River at Franconia, Chisago County; and (3391l [Hall, 1863, p. 130]) "St. Croix sand- 

 stone" at the mouth of Minneiska (Miniska) River, near the line between Wabasha and Winona counties; all in 

 Minnesota. 



(328h) Silico-calcareous layers of Fib of Owen [1852, p. 583], at the falls of St. Croix River, Polk County; (100) 

 "St. Croix sandstone" near Menomonie, Dunn County; (134) "St, Croix sandstone" in the lowest beds exposed along the 

 banks of Red Cedar River, opposite Menomonie, Dunn County; (82a) "St. Croix sandstone" 25 feet (7.6 m.) above 

 the water level near the Knapp, Stout and Company 's buildings, Menomonie, Dunn County ; (82s) " St. Croix sandstone' ' 

 on the bank of St. Croix River at St. Croix Falls, Polk County; (79, 79', and 79b) "St. Croix sandstone'' near Hudson, 

 St. Croix County; (83) "St. Croix sandstone" near Ti'empealeau, Trempealeau County; (78d) upper portion of "St. 

 Croix sandstone" exposed in the bluffs at La Crosse, La Crosse County; and (98 and 98x) "St. Croix sandstone" 

 near Eau Clane, Eau Claire County; all in Wisconsin. 



(9t) About 170 feet (52 m.) above the porphyry contact in the limestones of the Reagan sandstone, SE. J NE. J 

 sec. 2, T. 4 N., R. 13 W., 15 miles (24.2 km.) northwest of Fort Sill, Comanche County, Oklahoma. 



(14e) Limestone in Bartlett Hollow, 2 miles (3.2 km.) southeast of the mouth of Falls Creek, Burnet quadrangle 

 (U. S. Geol. Sui-vey), Lampasas County; (68 and 68z) limestone on Packsaddle Mountain, Llano County; (14b) lime- 

 stone on Cold Creek at north end of gorge opposite the north end of Sponge Mountain, 2 miles (3.2 km.) south of the 

 San Saba County line, in Llano County; (14c) upper part of the limestone exposed at Baldwin's ranch, on Cold Creek, 

 2.5 miles (4 km.) south of the San Saba County line, in Llano County; (67, 67c, and 67z) sandstone on Tatur Hill, 7 

 miles (11.2 km.) northwest of Burnet, Burnet County; (14q) sandstone in Bartlett Hollow, 1.5 miles (2.4 km.) south- 

 east of the mouth of Falls Creek, Burnet quadrangle (U. S. Geol. Survey), Lampasas County; (14r) lower 50 feet of 

 sandstone on Colorado River, 3 miles (4.8 km.) south of the northeast corner of Llano County; and (71) limestone in 

 Cold Creek Canyon, Burnet County; all in Texas. 



(92b) On Buffalo Creek, 2 miles (3.2 km.) southeast of Buffalo Mills, Rockbridge County, Virginia. 



Middle Cambrian: (302) Limestone east of West Gallatin (Gallatin) River, above Gallatin, Gallatin County, 

 Montana. 



(170) Sandstone about 10 miles (16.1 km.) south-southeast of Bald Mountain, Bighorn Mountains, Wyoming. 



(56f) Nounan limestone [Walcott, 1908a, p. 6], on a ridge 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. 



(3e) Thin-bedded limestone less than 400 feet (121.9 m.) above the quartzitic sandstones of the Cambria:n, at Ophir, 

 Oquin-h Range, Tooele County, Utah. 



(328e) "St. Croix sandstone" at St. Croix Falls, Polk County; and (83*) St. Croix sandstone at Trempealeau, 

 Trempealeau County; both in Wisconsin. 



Specimens somewhat doubtfully referred to Oholus matinalis occur at the following localities : 



Upper Cambrian : (lid) Arenaceous limestone about 2 miles (3.2 km.) north of Montana, in sec. 22, T. 35 N., R. 1 E., 

 Iron County, Missouri. 



Middle Cambrian: (319s) "St. Albans formation" at St. Albans, Franklin County, Vermont, 

 (lie) Thin-bedded limestones south-southwest of Potosi, Washington County, Missouri. 



Obolus matinalis (Hall) ? 



Plate VllI, figures 3, 3a. 



(For synonymy of Obolus matinalis, see page 400.) 



Oholus matinalis (Hall)?, Walcott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 325. (Mentioned as below.) 



A form indistinguishable from this species occurs in China in a gray limestone of Upper 

 Cambrian age. Only the general form of partly exfoliated shells is known. 



Formation and locality. — Upper Cambrian: (C54) Lower part of Chaumitien limestone [Blackwelder, 1907a, 

 p. 42 (part of last list of fossils)], near top of limestone knoll, 0.66 mile (1.1 km.) west of Tsinan, Shantung, China. 



Obolus membranaceus Walcott. 



I/' 



Text figures 36A-B, page 403. 



Oholus membranaceom Walcott, 1908, Smithsonian Misc. Coll., Vol. LIII, No. 3, p. 61, PI. VII, fig. 11. (Character- 

 ized and discussed as below as a new species. Fig. 11 is copied as fig. 36A in this monograph.) 



In size and outline this species is somewhat similar to Oholus feistmanteli (Barrande) (PI. XII, 

 figs. 1, la-c), but in its very thin almost membranaceous shell it differs from that species and 



