414 A. W. GRABAU PALEOZOIC DELTA DEPOSITS OF NORTH AMERICA 



shales. This formation apparently represents the Frankfort division, 

 though fossils have not been found. The terminal 350 feet of the strata 

 consists of soft gray and brown shales, alternating with black, slaty 

 shales, and carrying thin sandstone beds and occasionally ferruginous 

 limestones containing fossils. The following species are listed from these 

 beds by Collie (loc. cit., page 417) : 



. 1. Calymmene callicephala 



* 2. Cyrtolites ornatus Conrad 



3. Lophospira acuminata Ulrich 



4. Protoicarthia planidorsata Ulrich 



5. Trochonema nitidum Ulrich 



* 6. Hormotoma gracilis (Hall) 



* 7. Archinacella patelliformis (Hall) 



* 8. Modiolopsis modiolarvs Conrad 

 9. Ctenodonta pectuncaloides Hall 



flO. Orthodesma nasutum (Hall) 



*11. Cleidophorus planulatus (Conrad) 



fl2. Ctenodonta Virata (Hall) 



*13. Lyrodcsma poststriatum (Emmons) 



14. Byssonychia cincinnatiensis Miller 



15. OrthorhyncJiula linncyi (James) 



16. Raftnesquina squamula James 



17. Dalmanella testudinaria multisecta Meek 

 fl8. Zygospira modesta Hall 



19. Platystrophia lynx (Eichwald) 



20. Arthropora scliafferi Meek 



We recognize here a number of characteristic species of the Pulaski 

 shales of New York. These have been marked by an asterisk (*), others 

 marked by a dagger (f ) being more characteristic of the Trenton of New 

 York. In the Cincinnati region numbers 1 and 7 occur in the Upper 

 Trenton or Point Pleasant beds, number 1, Calymmene callicephala, fur- 

 ther ranging through the entire Cincinnatian (Eden to Richmond, in- 

 clusive), as does also number 18. Dalmanella multisecta (number 17) 

 and Cleidophorus planulatus (number 11) range through the entire 

 Eden, the first extending also into the Mount Hope member of the Lor- 

 raine. Number 2 ranges through the entire Maysvillian of the Cincin- 

 nati region and into the Lower Richmond. Numbers 7 and 13 occur in. 

 the lowest or Economy member of the Eden, numbers 4, 5, 7, 16 in the 

 middle or South gate member of the Eden, numbers 9, 17 in the lowest 

 Maysvillian (Mount Hope member), numbers 8, 9, 10, 15, and 16 in the 

 second or Fairmount member, and number 20 in the fourth or Corryville 

 member of the Maysvillian, while Platystrophia lynx (number 19 = 

 P. ponderosa, Foerste) is the typical fossil of the Mount Auburn or 



