220 CAMBRIAN BEACHIOPODA. 



98a. Upper Cambrian: "St. Croix Bandstone" at Marine Mills, on St. Croix River, Washington County, Minn. 



Ptychoparia sp. 



Ptychaspis granulosa (Owen). 



Lingulella mosia. 

 Dicellomus politus. 

 Billingsella coloradoensis. 



98x (=98, though from a slightly different horizon). (Cooper Curtice, 1884.) 

 Obolus matinalis. I *Lingulella phaon. 



Lingulella mosia. I Dicellomus politus. 



99. Upper Cambrian: "St. Croix sandstone" atMinneiska (Miniska), on Mississippi River, near the line between 



Wabasha and Winona counties, Minn. (Cooper Curtice, 1884). 

 Syntrophia primordialis. 



99a. Upper Cambrian: "St. Croix sandstone" near Pilot Knob, Adams County, Wis. (Cooper Curtice, 1884). 

 Lingulella mosia. 



Lingulella (Lingulepis) acuminata. 

 Eoorthis remnicha winfieldensis. 



100. Upper Cambrian: "St. Croix sandstone" near Menomonie, Dunn County, Wis. (Cooper Curtice, 1884). 



Lingulella winona convexa. 

 Dicellomus pectenoides. 

 Dicellomus politus. 

 Billingsella coloradoensis. 



Obolus matinalis. 

 Obolus sp. undt. 

 Lingulella ampla. 

 Lingulella mosia. 



100a. Upper Cambrian: "St. Croix sandstone" at Ettrick, Trempealeau County, Wis. (Cooper Curtice, 1884). 

 Dicellomus politus. 



101 (25 feet above 101a; same horizon as 102). (For stratigraphic position and association, see p. 147.) Middle 



Cambrian: Rogersville shale just above the road in the hill west of the schoolhouse 3.5 miles (5.6 km.) 

 southwest of Rogersville, on the road to Melinda Ferry [see Keith, 1896a, areal geology sheet], Hawkins 

 County, Tenn. (R. R. Gurley, 1887). 



Micromitra (Iphidella') pannula. 



Obolus lamborni minimus. 



101a (25 feet below 101). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Rogersville 

 shale just above the road in the hill west of the schoolhouse 3.5 miles (5.6 km.) southwest of Rogersville, on 

 the road to Melinda Ferry [see Keith, 1896a, areal geology sheet], Hawkins County, Tenn. (R. R. Gurley, 

 1887). 



*Obolus lamborni minimus. 



Lingulella desiderata. 



*Acrotreta rudis. 



101b. (For stratigraphic position and association, see p. 147.) Middle Cambrian: Rogersville shale just east of 

 the schoolhouse 3.5 miles (5.6 km.) southwest of Rogersville, on the road to Melinda Ferry [see Keith, 1896a, 

 areal geology sheet], Hawkins County, Tenn. (R. R. Gurley, 1887). 



Obolus lamborni. 



Obolus willisi. 



Lingulella desiderata. 



102 (same horizon as 101). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Rogersville 



shale just south of road 0.5 mile (0.8 km.) southwest of Rogersville, on the road to Melinda Ferry [see 

 Keith, 1896a, areal geology sheet], Hawkins County, Tenn. (R. R. Gurley, 1887). 



Obolus lamborni. 



Dicellomus appalachia. 



102c. (For stratigraphic position and association, see p. 147.) Middle Cambrian: First shale south of the Estill- 

 ville pike, 3.5 miles (5.6 km.) east of Rogersville, Greeneville quadrangle (U. S. G. S.), Hawkins County, 

 Tenn. (R. R. Gurley, 1887). 

 Acrotreta rudis. 



103 (below 103a). (For stratigraphic position and association, see p. 147.) Middle Cambrian: Second shale south 



of the ridge of sandstone in the Rome formation ("Town Knobs"), on the road from Rogersville to Dodson 

 Ford, near the line between the Morristown and Greeneville quadrangles (U. S. G. S.), Hawkins County, 

 Tenn. (R. R. Gurley, 1887). 

 Obolus lamborni. 



