FRANKLIN COUNTY. 627 



NucleocrinuB Verneuili belongs between two flint courses just under the 

 bone-bed. It is very abundant in this horizon. 



Platyceras dumosum is also found abundantly in the same stratum, but 

 it may not be limited to it. 



Spirifera maia has been found only in the lowest courses of the Dela- 

 ware beds. The same is true of Athyris vittata, which occurs in the bone- 

 bed. 



Grammysia bi-sulcata occurs near the bottom of the Delaware beds, but 

 is rarely met. 



Rhynchonella Carolina belongs very near the bone-bed — is found some- 

 times, indeed, in it. 



The only tentaculite known in the system {TentaculiUs spA) belongs 

 in the Delaware beds, and mainly in the uppermost portions. 



In the fifteen feet below the bone-bed the following forms are found. 

 Those marked with a star are not known to occur elsewhere, but more 

 extended observations on these points are necessary : 



Spirifera acuminata. 

 Spirifera manni* 

 Spirifera duodenaria* 

 Spirifera gregaria. 

 SiropTuymena rhomioidalis. 

 Strophodonta hemispherica. 

 Chonetes laiicosta." 

 Atrypa reticularis. 

 Nucleoapira condnna.* 

 Plalyceras dumosum.'' 

 Froeins planimarginatm. 

 Dalmania Ohioensis, 

 Phacops bufo. 

 Nucleocrinus Vemeaili.* 

 Cysiiphyllum Americanum." 

 Favositee. 



Gyathophyllum Zenkeri T 

 JSridopliyUum Vernemlanum." 

 Feneatella. 



Allusion has already been made to the peculiar interest with which 

 the remains of ancient fishes, contained in the Corniferous limestone, 

 must be viewed. They mark the, presence of a higher type of animal 

 life in this formation than any of the strata below it contain. They 

 constitute the lowest and oldest remains of vertebrates that we meet in 

 ascending the geological scale of the continent. The vertebrate type 

 appears here as well as elsewhere in its lowest class, viz., Fishes. 



