OF DEMSON UNIVERSITY 4^ 



characteristic species. At Lodi, Medina County, occurs thirty feet of 

 argillaceous shale full of concretions, and in it are found four species 

 which occur at Moots' Run, Licking County, viz : FrnestdlahcrrUkana, 

 Rhombopora ohioeusis, Pterinopeeten carinifcnis, and Tenbratiita / ituon- 

 sfans, while Cvrtinia aciitirostris which occurs in the nodule layer at 

 Wooster is also collected here. This stratum is about 125 feet below 

 the carboniferous conglomerate. It would thus seem that although the 

 fauna at Lodi differs considerably from that of Moots' Run, the differ- 

 ence could be accounted for, by the gradual disajjpearance of species 

 and new forms taking their place. We would correlate the Cuyahoga 

 shale with its equivalents farther south in the same manner as the 

 concretionary zone, as there is no reason to think that the Wuverly 

 strata, which were deposited subsequently, did not sustain the same 

 relation to each other as when the concretionary stratum was deposited. 

 The Cuyahoga shale, however, seems to have included elements above 

 any of its equivalents in Central Ohio. For example, Entoliuin avicu- 

 latiini and several species of Aviculopedcn, which have affinities with 

 coal measure forms. The different physical conditions under which 

 the Cuyahoga shale was deposited necessarily brought in new forms, as 

 Allorisma cnyaJwga, htitoHiim avicuhitum^ Solcnomxa cuxaho^aensis^ and 

 Macrodon tcnnistriata, and several other species which are not found 

 farther south. It has also some species which occur in the Waverly of 

 Central Ohio, viz : Niicida houghtoni, which has a range from thirty- 

 five feet below conglomerate I to five feet above conglomerate II, 

 Spirifer hiplicatii^, which is found in the middle jiart of division HI. 

 Conidaria iicwberryi, which ranges from II i to III2, and Plcitrotoma- 

 ria Stella, which is found in IIIi. These species will serve to illus- 

 trate the composite nature of the Waverly as rcpresenleil in liie Cuya- 

 hoga valley at and above the Big Falls. 



It has been suggested in volume IV, i)age 103, of the iUilletin of 

 Denison University, and in Vol. VI, page 37, of the Ohio Geological 

 Survey, that the Cuyahoga shale as exposed in the valley of the Cuya- 

 hoga, should be separated on account of lithologicai and palaeonto 

 logical differences existing between the different i)ortions of tne series 

 as exposed in that locality. We will now describe the strata there, 

 giving their equivalents as represented in Central Ohio as nearly as 

 possible. It must be remem!)cred, however, that the three subdivi.s- 

 ions into which the series have been divided, blend into each other so 

 that no line can be drawn separating them. I^xtending from the Big 



