STROPHOMENID^. 795 



The specific name was given in honor of Mr. W. A. Finkelnburg. 



Formation and locality. — TTpper Cambrian: (78 and 78s) "St. Croix sandstone," quarry near St. Croix River 

 in subui'bs of Osceola, Polk County; (81) "St. Croix sandstone" 1 mile (1.6 km.) east-northeast of Devils Lake, Sauk 

 County; (81b) "St. Croix sandstone" near Devils Lake, Sauk County; and (83, 83', 135b, and 135c) « "St. Croix sand- 

 stone" near Trempealeau, Trempealeau County; all in Wisconsin. 



(339f) "St. Croix sandstone" near Minneiska (Miniska) on Mississippi River near the line between Wabasha 

 and Winona counties, Minnesota. 



i^'lNKELNBXJEGIA OSCEOLA (Walcott) . 

 Plate XCIII, figures 1, la-h. 



Orthis (Finkelnburgia) osceofa Walcott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 279. (Discussed essentially as below 

 as a new species.) 



The general form of this species is similar to that of EoortMs remnicJia (Winchell) except 

 that it is usually more transverse. It is a smaller shell, averaging for the ventral valve a 

 length of 8 mm. and width of 11 mm., while E. remnicha averages 12 mm. in length and 14 to 

 16 mm. in width in the adult shell. The radiating costse are more uniformly rounded and 

 regular, and more numerous, except when compared with the variety texana. The shell of 

 Finkelnburgia osceola is tliick, hke other forms of the genus, with a result that the vascular 

 markings are definitely outlined. In figure Id the vascular markings are beautifully shown; 

 also, the large main vascular sinuses so characteristic of many species of BiUingseUa. The 

 carchnal process and median septum are well brought out in the cast, figure If. Some of the 

 dorsal valves approach quite closely to those of E. remnicha sulcata (Walcott) . 



The specific name is derived from Osceola, Wisconsin. 



Formation and locality. — Upper Cambrian: "St. Croix sandstone " at the following localities: (78 and 78s) 

 Quarry near St. Croix River, in suburbs of Osceola, Polk County; (78b) 50 feet (15 m.) above St. Croix River, near 

 the landing at Osceola, Polk County; (79a) quarry and ledge 0.5 mile (0.8 km.) southeast of the county courthouse, 

 Menomonie, Dunn County; (80) 0.33 mile (1.1 km.) southwest of the railway depot, Menomonie, Dunn County; 

 (79b) near Hudson, St. Croix County; (80a) 4 miles (6.4 km.) north of Reedsburg, Sauk County; (83, 83' and 135c)6 

 Tiear Trem,pealeau, Trempealeau County; (85x) near Mazomanie, Dane County; and (388i) 0.33 mile (1.1 km.) west 

 of the railway station, Lodi, Columbia County; all in Wisconsin. 



(339g) Just below the Dicellocephalus minnesotensis zone, near Winona, Winona County, Minnesota. 



(341) Sandstone near Lansing, Allamakee County, Iowa. 



Finkelnburgia osceola coreugata (Walcott). 



Orthis (Finkelnburgia) osceola corrugata Walcott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 280. (Characterized as below 

 as a new variety.) 



At two of the localities at which FinTcelnhurgia osceola (Walcott) occurs there are also found 

 a few specimens with strong concentric ridges formed by the piling up of lines of growth. The 

 shefi has a corrugated appearance that is very distinctive, and it is designated a variety. 



Formation and locality. — TTpper Cambrian: (78 and 78s)6 "St. Croix sandstone," quarry near St. Croix River, in 

 the suburbs of Osceola, Polk County, Wisconsin. 



(339g) Just below the Dicellocephalus minnesotensis zone, near Winona, Winona County, Minnesota. 



Superfamily STROPHOMENACEA Schuchert. 



Family STROPHOMENIBJE King. 



Subfamily RAFINE8QUIN.iE Scliucliert. 



Genus EOSTBOPHOMENA Walcott. 



[ijiir, davm; and Strophomena (<rTpe^i, a twist; and ^ijinj, the moon, a crescent).] 



Strophomena {Eoslrophomena) Walcott, 1905, Proc. U. S. Nat. Mus., vol. 28, p. 256. (Characterized as below as a 



new subgenus.) 

 Eostrophomena Walcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, PL XI, and pp. 142 and 148. (Classification 



of genus.) 



ii83 is ttie type locality. i 83' is tlie type locality. 



