278 New York State Museum 



of the brachiopods Orthis, Leptaena and Strophomena; 

 the gastropods Raphistoma, Scalites and Bucania; the 

 cephalopods Orthoceras, Camcroceras and a Gonioceras; 

 the trilobites Harpes, Illaenus etc. ; the calcareous alga, 

 Solenopora compacta etc. The Upper Chazy (C) has a 

 total thickness of 202 feet and is characterized by the 

 small, plicated rhynchonelloid brachiopod Camaratoechia 

 plena, having besides in its basal part species of large 

 straight and coiled cephalopods, Orthoceras, Cameroceras, 

 Oncoceras and Tarphyceras and the trilobite Glaphurus. 

 Throughout most of the Champlain valley the limestones 

 show quite a pure character and are commonly fine- 

 grained. The so-called black marble of Isle La Motte in 

 Lake Champlain is Chazy. 



The Pamelia limestone (Cushing '08) in central New- 

 York is of an age intermediate between the Middle and 

 Upper Chazy of the Champlain valley (= Depauville 

 waterlime, Emmons '40). It received its name from the 

 town of Pamelia in Jefferson county. The formation 

 consists essentially of limestone, though the bulk of it is 

 not pure limestone, with a thin basal sandstone followed 

 by shale (10-20 feet). These basal beds are weak and 

 seldom exposed. The maximum thickness of the forma- 

 tion is 125 to 150 feet and it is considered as the over- 

 lapping edge of the Chazy (Upper Stones River forma- 

 tion) from the southwest, not previously recognized in 

 New York State. The dove limestone beds in the upper 

 part of the formation have mud-cracked surfaces which 

 with the ostracod fauna and the presence of waterlimes 

 indicate shallow water and basin conditions. The lime- 

 stones of the lower portion, however, are fossiliferous 

 and indicate that there was a period of open water pre- 



