Art. II. Bownocker, Coniifci'oiLS Rocks of Ohio 37 
fully to 5. oiveni. It differs from the typical 5. acuminata in 
having a length of hinge line that approaches the maximum 
width of the shell, a broader sinus, and ribs that are not dicho- 
tomous. However, it may belong to 5. acurninata^ but if so 
presents a strongly modified form. 
Another point of interest is the rarity or absence of Lep- 
taenas and the Atrypas. 
The strata at this place are the most sparingly fossiliferous 
of any of this age in Ohio. The brachiopods are fairly well 
represented but that is the only group. Of the corals one spe- 
cies only is reported and the remaining great divisions present 
little better showing. Many of the most common forms else- 
where are here absent. The fauna is more closely related to 
that at White House than to any other. This is shown by the 
presence at both places of P. nacrea, C. hamiltonensis and G. 
crecta. These two places are the only ones where the first and 
last of these species are commonly found. Further evidence of 
a negative nature is furnished by the rarity or absence at both 
places of Atrypas and Leptaenas. 
RELATION OF THE FAUNA ABOVE THE BONE-BED TO THAT BELOW. 
As has already been stated the faunas above and below the 
bone-bed are fairly distinct. The difference, however, is not so 
great as at first appears; for more extensive collections show 
many species common to the two horizons. This point is well 
shown in the study of fossils from Delaware, Marion and San- 
dusky — all above the bone-bed. At Delaware the fauna is strik- 
ingly different from that below the bone-bed. This results from 
the presence of Lingula manni, Chonetes yandellanus, Leiorhyn- 
clius limitaris, Spirifera ziczac, Aviculopecten pai'ilis, Gi^ammysia 
bisulcata, Tentaculites scal'ariformis, and Gy^occras ohioense ; 
also by the absence of genera common below the bone-bed, 
such as Eridophyllum, Favosites (rarely present), Zaphrentis , 
Atrypa, Conocardium, Paracyclas, Callonema, EuomphaluSy Dal- 
manites, and Proetus. 
Proceeding north from Delaware, we find at Marion more 
of the forms above the bone-bed, which to the south occur be- 
