194 The Ohio Journal of Science [Vol. XYII, No. 6, 



east of Hillsboro, Ohio, contain a fauna quite distinct from that 

 found in the lower third of the West Union formation, northeast 

 of the Bisher dam, a mile southeast of Hillsboro, on Rocky- 

 Fork. It is sufficiently distinct to merit a separate designation 

 locally, and hence the name Lilley bed or member is here pro- 

 posed, to include both the clay shale and the underlying lime- 

 stone, since they contain the same fauna. Both the Zink and 

 the Trimble quarries are located on the western side of Lilley 

 hill, along the eastern edge of Hillsboro. For the underlying 

 part of the West Union formation the term Bisher member is 

 proposed, the typical fauna occurring northeast of Bisher dam, 

 a mile southeast of Hillsboro, and outcropping along the hillside 

 northward as far as the lower part of the valley immediately 

 southeast of the town. The most abundant fossil horizon is 

 about nine feet above the base of the formation, another 

 fossiliferous layer occurs from 12 to 20 feet farther up. 



Zaphrentis digoniata, sp. nov. Plate VIII, Fig. 1 A, B, C, D, 



E, F, G. 



Corallum strongly compressed laterally, the antero-posterior angle 

 varying from 40 to 45 degrees, and the lateral diameter equalling from 

 45 to b':) hundredths of the antero-posterior diameter. The two narrow 

 longitudinal ridges locating the position of the cardinal septum are 

 somewhat more conspicuous than the other longitudinal ridges marking 

 the exterior of the corallum, at least along the lower half of the corallum, 

 and are located along the posterior angle. The anterior and posterior 

 angles are equally well defined, and vary from almost acute, in some 

 specimens, to more or less strongly rounded. Frequently the specimens 

 are more acutely angled at the base and more strongly rounded toward 

 the top. The specimens usually do not exceed 35 millimeters in length. 

 The tip of the base of the corallum frequently curves slightly forward, 

 and the transverse striae also slope slightly downward from the rear 

 toward the front, on lateral view. 



The calice varies from 10 to 15 millimeters in depth. A deep but 

 narrow fossula is located on the cardinal side of the corallum and 

 extends as far as the center of the calice. The cardinal septum appears 

 to have varied greatly in the extent to which it extended inward from 

 the wall of the corallum toward the center of the calice. If alar fossulae 

 existed, these must have been shallow and inconspicuous. The number 

 of septa apparently varies in different specimens from 30 to 40, alter- 

 nating with an equal number of much smaller size, which could be 

 described as acute septal ridges. 



Zaphrentis digoniata is not rare in the two-foot clay shale and 

 in the upper part of the massive blue limestone, forming the 

 Lilley member of the West Union formation, at the Zink or 



