The Ciiiriinialiai! Series and its Brachiopods. 25 



sistent throughout both the Fairview and McMillan; among 

 them are Lepidodiscus cincinnatiensis, Hehertella sinuata, 

 and Platystrophia laticosta. Certain genera are character- 

 istic of the two formations as a whole. Platystrophia, 

 which is rare in the Eden,* is very abundant and charac- 

 teristic; Plectorthis is, with the exception of a single species, 

 P. plicatella, restricted at Cincinnati to these formations; 

 and Zygospira and Refinesquina, although found quite 

 frequently in the Eden and Richmond, are most abundant 

 in the Fairview and McMillan. Cyclonema, Lophospira 

 and Byssonchia are also common. 



The Fairview is divided into two, and the McMillan 

 into three members, based mainly on faunal content. The 

 members differ considerably in lithological character. 



Mt. Hope. — The Mt. Hope, named from its typical 

 exposure on Mt. Hope Road near the foot of Price Hill, 

 where the entire member is beautifully exposed, contains 

 about seventy-five per cent of shale. It resembles the 

 Eden, but the proportion of limestone is considerably 

 greater. As exposed on Straight St., west of the University, 

 the Mt. Hope has a thickness of about 50 feet. The type 

 fossil is Amplexopora septosa^ A single stratum containing 

 Strophomena planoconvexa marks the contact between the 

 Mt. Hope and the next higher member, the Fairmount.^ 

 On most exposures, the contact is difficult to locate, as this 

 fossil is not always present. 



Fairmount. — In the Fairmount limestone forms about 

 thirty-five per cent of the total thickness. About half of 

 this is suitable for building stone, and it is the limestone of 

 this division which is most commonly quarried in the vicinity 

 of Cincinnati. The Fairmount is the highest division 

 exposed on many of the lower hills about Cincinnati, as at 

 Fairmount, Hvde Park, and Avondale. It is also the 



♦Nickles states, Ky. Geol. Surv. Bull. 5, 1905, p. 32: "No Platystrophia has been noted 



in the Eden," but a few have been found in the Eden at Cincinnati. 

 tNickles: Jour. Gin. Soc. Nat. Hist., vol. 20, 1902, p. 76. 

 JNickles: loc. cit., p. 77. 



