GIRTY, GEOLOGIC AGE OF THE BEDFORD SHALE 305 



the general character of the typical Bedford fauna as represented in very- 

 complete collections. 



Before commenting on the characters of this fauna, as shown by my 

 list, it will be desirable to consider some species which have been recorded 

 from the Bedford and which I have not identified there. 



Newberry has cited the following species from the Bedford shale : 



Syringothyris typa Win. Hemipronites crenistria Phil. 



Orthis michelini Lev. Chonetes logani Hall 



Spiriferina solidirostris White Lingula cuyahoga Hall 



Macrodon hamiltoniw Hall Rhynchonella sagerana Win. 



upon which he comments in these words : 



"In this list there are several which have peculiar interest and significance,. 

 Syringothyris typa and Spiriferina solidirostris, for example, from the fact 

 that they are characteristic of the Lower Carboniferous rocks of other States, 

 while Orthis michelini is common to the Carboniferous formation all over our 

 country and in Europe." 



Herrick, 11 referring I doubt not to this passage, says : 



"Dr. Newberry has decided that the Bedford shale is Carboniferous on the 

 basis of such fossils as Syringothyris typa, Hemipronites crenistria, Chonetes 

 logani, Orthis michelina and Spiriferina solidirostris and a few more. Having 

 searched in the same localities without finding these forms in the typical Bed- 

 ford as it appears in southern Ohio and on the other hand finding the species 

 above mentioned [in a preceding list] we feel some hesitation as to the occa- 

 sion of the confusion. These species may indeed occur below the Berea, but 

 in flags and greyish shales not in the blue or red Bedford shale!" 



As to the closing remark I may say that though Newberry did not de- 

 scribe or figure the species which he named, there is, owing to the consti- 

 tution of the Bedford fauna, no reasonable doubt as to what types he 

 wished to indicate in each case, and Herrick is quite in error in supposing 

 that these species did not come from the true Bedford shale. 



Now, as to the species mentioned by Herrick, Orthis michelina and 

 Hemipronites crenistria are the species which I have listed as Schucher- 

 tella herriclci and Rhipidomella n. sp. The difficulty of discriminating 

 species among the Ehipidomellas and Schuchertellas is such that these 

 types are of minor importance in correlating faunas. The Waverly 

 Schuchertellas are so closely allied to S. chemungensis that it would de- 

 mand considerable temerity to say that a given suite of fossils belonged 

 to a species of the one fauna rather than to a species of the other and 

 indicated either Carboniferous or Devonian age. Much the same is true 



u Op. cit. p. 109. 



