THE DELAWARE LIMESTONE 429 



Thickness Total Thick- 

 No. (Feet) ness (Feet) 



4. From the "smooth layer" to the level of the Fishing 10J 323 



Club pond, which is mainly rather dark gray, fairly 



massive limestone. 

 3. Mostly covered from the level of the pond to the top 93 223 



of the cliff just below the highway bridge. 

 2. Zone of light gray, very fossiliferous limestone, at the 3! 13 



base of which are numerous specimens of Spirifer 



gregarius Clapp. 

 1. Rather dark gray, fairly massive limestone to the base 93 9! 



of the exposure, which formerly was about 7 feet 



above the level of the Scioto River. Zones 1 to 5, 



inclusive, are all in the Columbus limestone. 



In the brown shales of No. 6 of the above section the writer has 

 collected the following species : 



1. Liorhynchus limitare (Van.) Hall. 



2. Orbiculoidea lodiensis (Van.) Hall and Clarke. 



3. Orbiculoidea minuta (Hall) Beecher. 



4. Martinia maia (Billings) Schuchert. 



5. Tentaculites scalariformis Hall. 



6. Crinoid stem (small one). 

 At this locality Whitfield found : 



1. Liorhynchus limitare (Van.) Hall. 



2. Orbiculoidea minuta (Hall) Beecher. 



3. Lingula manni Hall. 1 



The range of the above species in New York is as follows: Lio- 

 rhynchus limitare (Van.) Hall is, perhaps, the most characteristic 

 species of the Marcellus shale; Orbiculoidea lodiensis (Van.) Hall 

 occurs in the Hamilton beds and Genesee shale; O. minuta (Hall) 

 Beecher, Marcellus shale; Martinia mala (Billings) Schuchert is 

 reported in the Onondaga limestone of Ontario ; Lingula manni Hall, 

 in the Delaware limestone of Ohio; and Tentaculites scalariformis 

 Hall, in the Onondaga limestone of New York. Of these species 

 Liorhynchus limitare is abundant, occurring more frequently than 

 any other; Orbiculoidea lodiensis and O. minuta are common, and 

 the remaining ones rare. It is to be noted that the abundant species 



1 Proceedings 0} the American Association for the Advancement oj Science, Vol. 

 XXVIII, p. 297. 



