OLENTANGY SHALE AND DEVONIAN DEPOSITS 483 



sculptilis, Leiorhynchus laura, Pholidops hamiltoniae, Pholido- 

 strophia iowaensis, Productella productoides, Rhipidomella 

 penelope, Rhipidomella vanuxemi, Schuchertella perversus, 

 Spirifer divaricatus, Spirifer mucronatus, Stropheodonta concava, 

 Stropheodonta demissa, Stropheodonta perplana, Pterinea flabel- 

 lum, Platyceras erectum, Tentaculites bellulus, Phacops rana 



Olentangy 

 Shale 



3. Shale, soft, gritless, blue, containing few fossils except in certain 



streaks or layers 19 o 



' FAUNA 



Microcyclas discus, Arthracantha punctobranchiata, Chonetes 

 lepidus, Pholidostrophia iowaensis, Platyceras erectum 

 2. Shale, soft, gritless, blue, with a few thin lenses of very fossilif- 

 erous crinoidal limestone. These beds include a thin zone in 

 which the fossils are small and always pyritized 6 o 



FAUNA (PYRITIZED) 



Leda rostellata, Nucula lirata, Nuculites triqueter, Paracyclas 

 lirata, Bactrites arkonensis, Tornoceras uniangulare 



FAUNA (NON-PYRITIZED) 



Arthracantha punctobranchiata, Gennaeocrinus arkonensis 

 Palaeaster eucharis, Chonetes deflectus, Chonetes lepidus, Chonetes 

 scitulus, Cyrtina hamiltonensis , Parazyga hirsuta, Produdella 

 spinulicosta, Schuchertella perversus, Spirifer mucronatus, 

 Actinopteria boydi, Glypodesma erectum, Bellerophon triliratus, 

 Platyceras erectum, Platyceras rarispinosum, Platyceras sub- 

 spinosum, Pleurotomaria delicatula, Styliolina fissurella, 

 Tentaculites attenuatus, Tentaculites bellulus, Primitiopsis 

 punctulifera, Phacops rana 

 1. Covered interval to the level of the Ausable River 10 o 



The most important point of similarity between the Ohio and 

 Ontario sections is to be found in the fauna of the thin layer about 

 25 feet below the base of the Prout limestone, and at a similar dis- 

 tance below the Encrinal limestone of Ontario. In both cases 

 the fossils are pyritized and of small size. Although the fauna of 

 this layer is somewhat more limited in Ohio, the four species that 

 have been found in it are identical with those of the similarly 

 located layer of the Arkona section. At no other horizon has this 

 fauna been found in Ohio, and three of the species have not been 



