378 New York State Museum 



colors. This limestone has a thickness of 20 to 50 feet 

 or so ; at Port Ewen the thickness is about 30 feet, in 

 the Catskill area about 20 feet, 25 feet at Becraft moun- 

 tain, 10 to 15 feet at Schoharie. The fossils are more 

 silicified than in the Becraft below. In the field two 

 fossils will always distinguish it from the Kalkberg, the 

 brachiopod Spirifer concinnus and the bryozoan Mono- 

 trypa tabulata. The fauna is a modified Becraft fauna. 

 The Port Ewen beds (Clarke '03) are a series of shaly 

 limestones lying above the Alsen limestone and similar 

 in character and fossil content to the shaly limestones 

 (New Scotland) underlying the Becraft. When first 

 shown to be a unit they were described as the "Upper 

 Shaly beds" (Davis '83). Later (Clarke and Schuchert 

 '99) changed the name to Kingston beds, but as the 

 name was preoccupied they were later called Port Ewen 

 beds from the town of that name, opposite Rondout, 

 where they are best exposed. They have their best de- 

 velopment in southeastern New York where the maxi- 

 mum thickness is about 200 feet. These beds are missing 

 in the Helderberg sections northwest of the Catskill area 

 and at Schoharie beds formerly considered Port Ewen 

 are now considered Alsen limestone. At Rondout the 

 Port Ewen has a thickness of about 150 feet, 30 to 35 

 feet in the Saugerties region and five or six feet in Aus- 

 tin's Glen, Catskill. These limestones are darker and 

 more argillaceous than the Alsen, the dark color of the 

 fresh rock usually turning gray in weathering; they 

 are also less fossiliferous than either the Alsen or the 

 New Scotland. A list of some of the fossils will show 

 the similarity of the fauna to that of the New Scotland. 

 The brachiopods Spirifer concinnus, S. cyclopterus, 

 rarely S. macro pleura, S. (Delthyris) perlamellosus, 



