An Account of the Middle Silurian Rocks of Ohio and Indiana. 



171 



the purplish sandy layers seen at the top of the Clinton at Todd's 

 Fork are seen. Under the Clinton is the Belfast bed; it has the same 

 light yellowish brown color as at Spring Hill, though bluish tints 

 are also seen. Its thickness is between four and a half and five 

 feet. The blue clay layer beneath was not seen. It was probably the 

 weak resistance of this blue clay layer which gave the glaciers a 

 chance to loosen the slab and to bring it from a short distance to 

 this point. I did not observe any gravel under the Belfast bed 

 anywhere but the slab is evidently out of place, and at present is 

 much crumbled. The chief interest of the slab lies in the presence 

 beneath it of the Belfast bed in its full thickness. 



9. Caesars Creek — four and a half miles south of Xenia, 

 where the Xenia and Wilmington pike crosses Caesar's Creek. 

 Numerous exposures occur on the northern side of the creek, a short 

 distance east of the pike. Only the lower six feet of the Clinton are 

 here exposed. It is chiefly crinoidal but contains also phases similar 

 to the denser white rock of the Clinton at Soldiers' Home. The latter 

 is usually abundantly forsilferous, and the following forms were found : 

 Illcznus daytonensis, Illcenus ambiguus, Calymene vogdesiy large form, gla- 

 bella, Lichas brevicepts, Leptcena rhomboidalis, Strophomena tenuis, Stropho- 

 mena patcnta, Ort/iis calligraninia , the large Soldiers' Home form, 

 Meristella umbonata, Atrypa marginalis, common, Ptilodictya lanceolata, 

 var america?ia, and probably also Ptilodictya whitfieldi, Clathrofora 

 frondosa, common, Phainopora cxpansa, Pluenofora magna, Pachydictya 

 bifurcata, Pachydictya obesa, of which P. turgida is probably only the more 



branching form, Rhinopora verrucosa, Hemitrypa ulrichi, Phylloporina 

 angulata, Favosites niagarensis and Haly sites eaten ulatus. 



Under the Clinton lie about five feet of the typical Belfast bed. 

 Its color is bluish when fresh, but long weathering has made most of 

 the rock at this exposure brownish in color. The only fossils recog- 

 nized in it were fucoidal markings, and casts of crinoid stems, the 

 lime having leached out. Below this for about six feet there is no 

 exposure. Under this in the bank of the stream are six feet of a 

 shaly material, being brownish at the top, and bluish and more 

 clayey farther down. At its base is a firmer course, about 8 inches 

 thick, resembling the Belfast bed in texture. Below it there is a 

 purplish clay, shaly parted, at times mottled with blue. It will be 

 noted that no recognizable fossils were found in that part of the 



