Handbook of Paleontology 377 



is extensively quarried for Portland cement, has a thick- 

 ness of 45 feet. At Rondout there are 35 feet of this 

 limestone. In the Helderberg area the beds vary from 

 nine to 27 feet, only the lowest beds (nine feet) with 

 shale seams appearing in the Indian Ladder area. At 

 Schoharie there are about 15 feet of Becraft. There 

 are some very characteristic fossils as the shieldlike crin- 

 oid base or anchor Aspidocrinus scutelliformis, which is 

 found throughout the Becraft, sometimes in great 

 abundance, and also occurs in the upper New Scotland. 

 The brachiopod Sieberella (Pentamerus) pseudogaleata 

 is also abundant and characteristic. Among other 

 brachiopods commonly found are Atrypa reticularis, 

 Spirifer concinnus, Uncinulus nobilis and Schizophoria 

 multistriata ; less commonly Leptaena rhomb oidalis, Un- 

 cinulus campbellanus, Rhipidomella oblata, Wilsonia 

 ventricosa, Meristella princeps. A number of gastropods 

 occur but they are not at all abundant. One of the 

 commoner forms is Trematonotus profundus. 



The Alsen limestone (Grabau '19) is the name pro- 

 posed for cherty limestones which overlie the Becraft 

 and bear the same relation to it as the Kalkberg does 

 to the Coeymans. It was originally included in the Port 

 Ewen as a basal phase. The formation was named from 

 the section at Alsen, N. Y. (where the Port Ewen is 

 absent) and is well shown in the hills about Alsen, in 

 Becraft mountain and at Schoharie. At Becraft mountain 

 and Schoharie it is followed by the Oriskany sandstone, 

 at Kingston and Port Ewen by the Port Ewen beds. The 

 Alsen, like the Kalkberg, is a more impure limestone 

 than the beds below. Basal Alsen is light colored but 

 finer-grained than the Becraft, but it quickly becomes a 

 dark blue-gray in color, often weathering into buff 



