180 



CAMBRIAN BRACHIOPODA. 



12j (50 feet below 12g; 40 feet above 12i). (For stratigraphic position and association, see p. 142.) Upper Cam- 

 brian: Lower part of Arbuckle limestone, second fossiliferous horizon in the section at Small Hill, 2 miles 

 (3.2 km.) southwest of Signal Mountain, about 8 miles (12.8 km.) west of Fort Sill, Comanche County, Okla. 

 (E. 0. Ulrich, 1901). 



Eoorthis wichitaensis. 

 Agraulos sp. 

 Dikellocephalus sp. 



Ptychaspis sp. 

 lUaenurus sp. 



12k (15 feet below 12n in Springer section). (For stratigraphic position and association, see p. 142.) Upper Cam- 

 brian: Limestone of the Reagan sandstone, about 225 feet (69 m.) above the porphyry contact and 55 feet 

 (17 m.) below the Arbuckle limestone, on the west side of Honey Creek, near southeast comer sec. 35, T. 1 S., 

 R. 1 E., 7 miles (11.2 km.) north of Springer, Ardmore quadrangle (U. S. G. S.), Carter County, Okla. (E. 0. 

 Ulrich, 1901). 



Obolus tetonensis ninus. 

 Lingulella similis. 

 Acrotreta microscopica. 

 *Eoorthis indianola. 



Eoorthis remnicha. 

 Eoorthis wichitaensis. 

 Eoorthis wichitaensis laeviusculus. 

 ChariocephaluB sp. 



12m. (For stratigraphic position and association, see p. 142.) Upper Cambrian: Arbuckle limestone [in the 

 section 7 miles (11.2 km.) north of Springer this horizon is about 30 feet (9.1m.) above the Reagan sandstone], 

 NE. 1 sec. 2, T. 2 S., R. 1 E., Ardmore quadrangle (U. S. G. S.), Carter County, Okla. (E. O. Ulrich, 1901). 



Obolus tetonensis ninus. 

 Lingulella similis. 

 Eoorthis remnicha texana. 



Agraulos sp. 

 Ptychaspis sp. 



12n (15 feet above 12k in Springer section). (For stratigraphic position and association, see p. 142.) Upper Cam- 

 brian: Limestone of the Reagan sandstone about 240 feet (73 m.) above the porphyry contact and 40 feet 

 (12 m.) below the Arbuckle limestone, NW. i sec. 1, T. 2 S., R. 1 E., 7 miles (11.2 km.) north of Springer, 

 Ardmore quadrangle (U. S. G. S.), Carter County, Okla. (E. O. Ulrich, 1901). 



Obolus tetonensis ninus. 



Lingulella similis. 



Lingulella (Lingulepis) acuminata. 



Acrotreta microscopica. 



Eoorthis indianola. 



Eoorthis remnicha. 



Eoorthis remnicha texana. 

 Eoorthis wichitaensis. 

 Eoorthis wichitaensis Iseviusculus. 

 Syntrophia primordialis. 

 Ptychoparia sp. 

 Chariocephalus sp. 



12p. (For stratigraphic position and association, see p. 142.) Upper Cambrian: About 225 feet (69 m.) above the 

 igneous rocks in the limestone of the Reagan sandstone, at the northwest extremity of the Arbuckle 

 Mountains, about 4 miles (6.4 km.) east of Homer, Carter County, Okla. 



Eoorthis remnicha. 



*Eoorthi8 wichitaensis. 



*Eoorthis wichitaensis Iseviusculus. 



Agraulos sp. 



Ptychoparia sp. 



Chariocephalus sp. 



Illsenurus sp. 



Obolus tetonensis ninus. 

 Lingulella similis. 

 Lingulella (Lingulepis) acuminata. 

 Acrotreta curvata. 

 Acrotreta microscopica. 

 *Acrotreta ulrichi. 

 Linnarssonella girtyi. 

 Eoorthis indianola. 



12q. (For stratigraphic position and association, see p. 147.) Upper Cambrian: Knox dolomite on Bunker Hill, 

 6 miles (9.6 km.) northeast of Rogersville [see Keith, 1905, areal geology sheet], Hawkins County, Tenn. 

 (M. R. Campbell, 1892). 

 *Syntrophia campbelli. 



12v. Lower Cambrian: Sandstone above the quartzite 1 mile (1.6 km.) west of Fruitville, on Little Conestoga 

 Creek, Manheim Township, Lancaster County, Pa. (C. D. Walcott, 1909). 

 Obolella crassa? 



13. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Sandstones of the Rome formation 

 1.5 miles (2.4 km.) east of Post Oak Springs [see Hayes, 1894, areal geology sheet], Roane County, Tenn. 

 (C. D. Walcott, 1891). 

 Lingulella ino. 

 •'Linnarssonella tennesseensis. 



13b. (For stratigraphic position and association, seep. 147.) Middle Cambrian: Sandstones of the Rome formation 

 northeast of Rhea Springs [see Hayes, 1894, areal geology sheet], Roane County, Tenn. (C. D. Walcott, 1891). 

 Micromitra (Paterina) crenistria. 

 'Lingulella ino. 



