Handbook of Paleontology 411 



upturned edges of older beds (Cambrian to Ordovician). 

 It has been correlated with the Shawangunk grit and also 

 the Oneida conglomerate, but recent studies (see Ruede- 

 mann '30) have shown it to be of Upper Devonian (Cats- 

 kill) age. 



Characteristic Devonian sections may be seen in the 

 Helderberg-Catskill area and in the Lake Erie area. In 

 the Kingston region of the former area the Coeymans 

 limestone lies above the Manlius (Upper Manlius or 

 Keyser, mainly). Then follow in succession the New 

 Scotland, Becraft and Alsett limestones, the Port Ewen 

 beds, the Oriskany (Glenerie) limestone, Esopus grit, 

 Onondaga limestone, Hamilton beds (Marcellus, Mount 

 Marion, Ashokan), Oneonta series, Catskill shales and 

 sandstones. In the Indian Ladder region, Helderberg 

 mountains, there are exposures showing formations from 

 the Upper Ordovician to the Middle Devonian (figure 

 52). In the Lake Erie section, the Onondaga limestone 

 rests unconformably upon the Cobleskill and is followed 

 in succession by the Hamilton (incl. Marcellus) beds, the 

 Tully limestone, the Genesee beds, the Portage beds 

 (which are replaced eastward by the Ithaca beds) and 

 finally the Chemung beds. 



The fossils. Characteristic fossils found in Devonian 

 formations are illustrated in figures 54 to 59 and are 

 listed below. 



