26 Cincinnati Society of Natural History. 



highest bed-rock on the hills back of Newport and Cov- 

 ington. On Straight St. where a good section is exposed, 

 this division is about 60 feet thick. While fossils are less 

 abundant in this member than either above or below, the 

 number of species represented is far greater, and the speci- 

 mens are better preserved. The bryozoan Dekayia aspera^ 

 is the type fossil of this member, while Glyptocrinus deca- 

 dactylns, Callopora dallei, Constellaria constellata, Platy- 

 strophia crassa, Modiolopsis modiolaris, Cyclonema mediale, 

 and Lophospira ampla are characteristic. 



Bellevue. — The lowest member of the McMillan forma- 

 tion is the Bellevue, a division lithologically and faunally 

 different from the underlying and overlying strata. It has 

 a thickness of only 20 feet. The lower 15 feet is composed 

 almost wholly of limestone which is made up largeh" of a 

 frondlike bryozoan, Monticulipora molesta. This horizon 

 is more resistant than the upper part of the Fairmount on 

 which it rests, so that it stands out prominently on the faces 

 of many of the bluffs around Cincinnati. The upper 5 feet 

 of the Bellevue is composed of thin-bedded shales and shaly 

 limestones. These shaly limestone beds are made up 

 almost entirely of single valves of Rafinesquina alternata 

 fracta, with clay partings between the shells. On weather- 

 ing, the clay partings break down leaving a jumbled mass 

 of poorly preserved shells. This horizon, known as the 

 "fracta zone," is one of the most easily recognized horizons 

 of the entire Maysville. It is less resistant than the lower 

 part of the Bellevue and usually forms a steep slope at the 

 top of the projecting cliff. The type fossil of the Bellevue, 

 Monticulipora molesta, is present, although not as abundant 

 as in the lower fifteen feet. Platystrophia laticosta is common 

 throughout the "fracta zone," and Hehertella sinuata, 

 Rafinesquina alternata, and a number of molluscs are abun- 

 dant in the lower part of this horizon. 



Corryville.^-The Corryville member of the McMillan, 

 which is 60 feet thick, includes a series of thin limestones 



*Nickles: loc. cit., p. 77. 



