96 The Fauna of the Magnesian Series. 



Lingula wiaona Hall. 



Lingala winona Hall, 16th Annual Report New York Museum of Nat- 

 ural History, p. 126, pi. VI. fig. 9, 1863. 



This species was described by James Hall from specimens obtained at 

 Lansing, Iowa, "occurring more than two hundred fest below the Lower 

 Magnesiaa limestone and near the middle of the Potsdam sandstone." 

 The specimens here identified with it occur in numbers with other Lingula in 

 the Saint Lawrence formation near Osceola, Wisconsin, and other places 

 along the Saint Croix river. They have the sub-quadrate outline, a thick 

 shell and show a deep pedicel groove. 



Orthis {Billingsella) pepina Hall. 



Ortbis pepina Hall, 16th Annual Report New York State Museum of 

 Natural History, p. 134, pi. VI, figs. 23 to 27, 1863. 



Orthis pepina Whitfield, Geology of Wisconsin, vol. IV, p* 170, pi. I, 

 figs. 4 and 5. 1882. 



Orthis (Bilingsella) pepina Hall (1892), Palaeontology of New York^ 

 vol. VIII, pt. I, p. 230, pi. YII, a, figs. 1-9. 



This species is found at Osceola, Wisconsin, and vicinity in the Jordan 

 sandstone and it occurs also in the Oneota dolomite a few miles further 

 south, near Stillwater, Minnesota. It occurs also in the Saint Lawrence 

 formation. 



Belleropbon antiquatus W^hitfield. 



Belierophon antiquatus Whitfield, Annual Report for 1877, Geological 

 Survey of Wisconsin, p. 52; and Geology of Wisconsin, vol. iv, p. 176, pi. I, 

 figs. 13 and 14, 1882. 



Described by Mr. Whitfield from the " soft friable sandstone of the 

 Potsdam group at Osceola Alills, Wisconsin." It has not yet been found 

 on the Minnesota side of the Saint Croix river, although specimens have 

 been found in the Jordan sandstone at the locality cited. 



Euomphalus winonensis n. sp. 

 Plate VI, figure 1. 



Shell of more than two and one-half volutions; rapidly expanding and 

 in contact for about two volutions. The apex and flattened surface are 

 nearly in the same plane. The suture is deep and the umbilicus wide. Ap- 

 erature circular except for a deep notch on the upper outer margin, the suc- 

 cessive stages of which have produced an angular keel, a flattened upper 

 surface to the coil and a slightly concave band just beneath the keel. On 

 the volutions that are in contact the upper inner surfaces are concave or 

 of reduced convexity. The surface is marked by strong, irregular lines of 

 growth, which curve obliquely back on cither side of the keel, forming an 

 angle at the acute edge of the carina. The shell was apparently very thin, 

 and the apical portion of it was either filled solid or crossed by strongly 



