OE DENISON UNIVERSITY 



43 



tabular arrancjement based on the original descriptions will afford the 

 basis for comparison. The following order being preserved: 



I. S. striatiformis, 2. S. centronata, 3. S. marionensis, \. S. 

 biplicatus. 



Narrow, low, 



Numerous, small, 

 round, bifrc'tinjr 





Minute 



Between S. marionensis and S. centronata it is very hard to dis- 

 cover any point of dissimilarity. In fact we cannot distinguish sj)eci- 

 mens from the Cuyahoga shale, the locality of S. centronata, from 

 specimens of S. marionensis from near the middle of the lower divis- 

 ion of the Waverly in Licking Co. . S. striatiformis is restricted to the 

 upper portion. 



Spirifer inarionrnsis, Shumani. 

 (Phte VI, Figs 3-1; Plate VII. Kig n; Pi-ite L\. Im^. : ?) 



Cf. S. centronata. Win. 



Our figures give a good idea of the range of variation e.\hil)ited, 

 though in the smaller shells the mucronate e.xtension of the hinge is 

 more marked. On the largest shells there are rarely more than four 

 plicce on the fold or sinus and the lateral margins are usually (juite 

 oblique. This species has been found in the shale near the cast end 

 of the bridge crossing Moot's run, four miles west of Granville, and 

 the layer of nodules one mile west. The horizon being supposed to 



