1 6 Bulletin of Laboratories of Denison 'University [Voi. xt. 
the names are not significant. Collections were made here with 
a view of determining the vertical range of the species. On 
tabulating these, it was found that the most common specimens 
usually range throughout the entire series below the bone-bed, 
while the less common ones have a more restricted range. Fur- 
ther the species may be divided into three groups, one occupy- 
ing the upper lo feet and terminating with the “smooth rock”; 
the second occupying all below this, and the third ranging 
through both. These points are shown on the accompanying 
tables. Plates III and IV. The following lists show the species 
that are found in each horizon : 
Top Beds. From bone-bed to lo feet below.— f- Clado- 
pora sp., Clathropora sp., Eridophyllum verneuilanum. E. & 
H., Eridophyllum simcoense. Bill, Heliophyllum halli. E. & 
H., Hadrophyllum d’orbignyi. E, & H., Zaphrentis gigantea. 
Leseur., Zaphrentis ovalis. H., Zaphrentis prolifica. Bill., Nu- 
cleocrinus verneuilanum. Troost. , Codaster pyramidatus. 
Snum., Leptaena rhomboidalis. Wilch., Productella spinuli- 
costa. H., Orthotetes chemungensis. Con , Spirifera acuminata. 
Con., Spirifera fimbriata. Mort., Spirifera gregaria. Clapp., 
Pentamerella arata. Con., Glyptodesma erecta. Con., Sanguin- 
olitj^ (?) sanduskyensis (?) H., Platyceras dumosum. Con. 
Bottom Beds. Lying beneath Top Beds.-;- Stromatopora 
sp. Cystiphyllum americanum. E. &H., Rhipidomella livia. Bill., 
Stropheodonta concava. H., Stropheodonta demissa. H., Spir- 
ifera raricosta. Con., Modiomorpha perovata. M. & W., Para- 
cyclas elliptica. H., Pterinea pinguis. H., Murchisonia desider- 
ata. H., Isonema humilis. M., Callonemal ichas. H., Euomph- 
alus decewi. Bill., Gomphoceras eximium. H., Gyroceras ohio- 
ensis, Phacops cristata. H. . 
Both Horizons. From bone-bed to bottom of quarry. -f- 
Favosites hemisphericus. Troost., Atrypa aspera. Schloth., 
Atrypa reticularis. Linn., Chonetes mucronatus. M. & H., 
Schizophoria propinqua. H., Stropheodonta hemispherica. H., 
Stropheodonta patersoni. ' H., Stropheodonta perplana. Con., 
Spirifera manni. H., Conocardium cuneus. Con., Dalmanites 
aspectans. Con. 
