May, 1919] Silurian Fossils From Ohio 375 



between the West Union Cliff and the Upper or Blue Cliff, as 

 drawn by Orton at Hillsboro. Moreover, if Hillsboro is to be 

 considered as the type area for the Lower Cliff of Orton, the 

 latter oughtto receive a name taken from the Hillsboro area. 

 Therefore, the name Bisher has been chosen. However, at any 

 distance from the Hillsboro area, it has proved so rarely possible 

 to discriminate the Bisher and Lilley members, if indeed the 

 latter is present, that a collective term seems desirable. For 

 this service the term West Union, used by Orton, has been 

 regarded as serviceable and as much more in keeping with the 

 exposures at West Union, Ohio, where no trace of th-e Lilley 

 member can be identified. 



Dinobolus conradi (Hall). 

 Plate XVII, Fig. 6. 



A cast of the interior of the pedicel valve, found in the 

 Cedarville dolomite, in the most eastern of the Mills quarries, 

 southwest of Springfield, Ohio, is here figured. This species 

 was described originally from the Leclaire limestone at Leclaire, 

 Iowa, and from the Racine limestone at Racine, Wisconsin. 

 It makes its appearance in Wisconsin as early as the Lower 

 Coral beds, in the lower part of the Waukesha beds, which lie 

 beneath the Racine limestone. In Ohio this species has been 

 known hitherto only from the single individual, from the 

 Niagaran at Crawford, in Wyandot county, figured by Hall and 

 Whitfield in the second volume of the Palaeontology of Ohio, 

 in 1875. This locality lies about 70 miles north of Springfield; 

 here it is associated with Megalomus canadensis and casts of 

 Trimerella, suggesting an age corresponding with that of the 

 'Megalomus beds of Highland and Adams counties, in southern 

 Ohio. 



Schuchertella prosseri Sp. nov. 

 Plate XVI, Figs. 1 A-E. 



At the Whitfieldella horizon, nine feet above the base of the 

 Lower of Bisher member of the West Union formation, about a 

 mile southeast of Hillsboro, Ohio, along the hill-front northeast 

 of the Bisher dam bridge, a large species of Schuchertella is 

 common. Occasional specimens occur also near Danville, 

 and a half a mile west of Port William, Ohio. Among described 

 species, this lower West Union species resembles most the 

 Schuchertella tenuis described by Hall from the Waldron shale 

 of Indiana. 



