312 ('. SCHUCHERT — LOWEK RTELDERBEItG-ORISKANY FORMATIONS 



At Three Springs, in Huntingdon county, Pennsylvania, in a coarse. 

 friable sandstone, in the lower 30 feet, were found the following:* 



Hipparionyx proximua Vanuxem. Rensselseria marylandica Hall. 



Eatonia peculiaris (Conrad). Megalanteria ovalia Hall. 



Spirifer murchisoni Castelnau. Actinctpteria textilis (Hall). 



Spirifer arenosus (Conrad). Megambonia lamellosa Hall. 



Rensselseria oroides (Eaton J. Platyceras venlricosum Conrad. 



At Mapleton, Huntingdon county, Pennsylvania, on the Upper Juniata, 

 the Oriskany is about 150 feet thick. Spir\fer arenosus (Conrad) occurs 

 near the top, and from the lower half was secured — 



Katonia peculiaris (Conrad). Platyceras tortuosum Hall. 



Spirifer murchisoni Castelnau. Platyceras platyostoma Hall. 



Rensselseria ovoides (Eaton). IHaphorostoma ventricosa (Conrad). 



Bedford, Bedford county, Pennsylvania : 

 Diaphorostoma ventricosa (Conrad). 2063. 



Newry, Blair county, Pennsylvania : 

 Spirifer murchisoni Castelnau. 25362. Alrypa reticularis Linne. 25303. 



Near Chambersburg, Franklin county, Pennsylvania: 



Diaphorostoma ventricosa (Conrad). 3920. 



MARYLAND AND WEST VIRGINIA ORISKANY AND ITS FAUNA 



In western Maryland, the Oriskany occupies " the central division of 

 the Appalachian region " and enters into the formation of the Alleghany 

 plateau. It follows upon the Helderbergian series, and in turn is over- 

 lain by the " Romney formation," the equivalent of the New York 

 Hamilton. In Maryland, the Oriskany is known as the " Monterey 

 formation," and is described by Professor Clark f as follows : 



" The Monterey formation, so called for its typical occurrence at Monterey, Vir- 

 ginia, is confined, like the Upper Silurian formation, to the central division of the 

 Appalachian region in western Washington and Alleghany counties, Maryland. 

 The deposits of the Monterey formation are typically rather coarse-grained, some- 

 what friable sandstones, white or yellow in color. At times the materials become 

 very coarse grained, resulting in a clearly defined conglomerate, while at other 

 times, especially in the western portion of the area, the materials are fine-grained, 

 with here and there interstratified layers of coarse materials. The sandstone is 

 very fossiliferous and carries the typical Oriskany fauna of the north. The for- 

 mation has a thickness of about 300 feet." 



* [bid., p. noi. 



f W. B. Clark : Md. Geol. Survey, vol. i, 1897, pp. L82, 183. 



