86 The Middle Devokian Deposits of Maryland 



Pleurotomana (Bemhc.ria) siilco)iiarginala. Conrad, Fleiirotomaria (Tre- 

 pospira) rotalia Hall {?), DiapliorGstoma lineatiun (Conrad), ShjlioUiia 

 fissurella (Hall), Spyrocems crotalum (Hall), Spyroceras darl-ei Prosser, 

 Phacops rana (Green), Da-hiianiles mun/landictis Prosser. 



Exposure at McCoys Ferry. — At McCoys Perr}^ to the west of the south- 

 ern end of Xorth Mountain and 4 miles southwest of Clear Spring is the 

 most eastern outcrop of the Romney shales. The rocks are grayish and 

 somewhat arenaceous and are exposed to hest advantage by the side of the 

 highway under the Western Maryland Eailroad bridge. These shales are 

 very fossiliferous containing large numbers of Chonetes, especially fine 

 specimens of Chonetes coronatus (Conrad), Spvrifer mucronatus (Con- 

 rad), Tropidoleptiis carinatus (Conrad), Cyrtina liamiltonensis Hall, 

 and other species as follows : Stropheodonta (LeptostropJiia) perplana 

 (Conrad), Schuchertella variabilis Prosser, Chonetes mucronatus Hallj 

 Chonetes coronatus (Conrad), Chonetes setiger (Hall), Chonetes lepidus 

 Hall, Chonetes vicinus (Castelnau), Tropidoleptus carinatus (Conrad), 

 Cyrtina hamUtonensis Hall, Spirifer mucronatus (Conrad), Spirifer 

 granulosus (Conrad), Spirifer audaculus (Conrad), Spirifer acuminatus 

 (Conrad), Spiiifer angustus Hall ( ?), Falaeoneilo tenuistriata Hall ( ?), 

 Tentaculites attenuatus Hall. 



In this exposure the lithology and fauna agree so closely with the 

 typical Hamilton shales of ^STew York that there seems to be no oppor- 

 tunity for any question concerning the correctness of this correlation. 



In the immediate vicinity of McCoys Ferry, on the Chesapeake and 

 Ohio Canal, is an interesting cliff of Tuscarora sandstone. There are 

 exposures of blue, fairly arenaceous shales between the canal and the 

 Western Maryland Eailroad southwest of McCoys Ferry. The rocks are 

 less fossiliferous than those at the Ferry but certain layers contain a fair 

 number of species of brachiopods while pelecypods are more abundant 

 than in the preceding zone. These outcrops are probably higher in 

 the Pomncy formation than those at McCoys Ferry. The fauna is as 

 follows: Chonetes scitalus Hall, Chonetes setiger (Hall), Chonetes 

 vicinus (Castelnau), Tropidoleptus carinatus (Conrad), Spirifer mucro- 

 natus (Conrad), Prothyris lanceolata Hall, Grammysia hisulcata (Con- 



