Handbook of Paleontology 271 



is found. It has a maximum thickness in the Champlain 

 region of about 1500 feet (Shoreham, Vt.). These beds 

 were formerly included in the "Calciferous" group of the 

 Mohawk valley, part of which (division A and the basal 

 portion of division B, marked at the top by an uncon- 

 formity) is now placed with the Little Falls dolomite 

 (Ozarkian). The "Calciferous" of the Champlain valley 

 was studied by Brainerd and Seely ('90) and divided into 

 five divisions (A, B, C, D, E). The Beekmantown, as 

 restricted, comprises the upper part of B through E. 

 Thus division C, which has a thickness of 350 feet and 

 consists of thick beds of magnesian limestones alternat- 

 ing with thinner beds of calcareous sandstone is consid- 

 ered typical middle Beekmantown. The upper part of the 

 division D and the whole of E have been given the name 

 Cassin formation (Cushing '05) from the Fort Cassin 

 exposure. Except for a calcareous alga, Cryptozoon, fos- 

 sils are rare in the lower beds. The middle division is 

 rather abundantly fossiliferous. The flatly coiled gastro- 

 pod genus Lecanospira is particularly characteristic and 

 is found at a corresponding horizon in Quebec, northwest 

 Scotland, through the Appalachian valley to central Ala- 

 bama, in Missouri, Oklahoma, Texas and in the Cordil- 

 leran region far northwest toward the Arctic (Ulrich). 

 In the upper beds are found cephalopods of the Endo- 

 ceras type and other forms, and gastropod genera as 

 Ophileta and Eccyliomphalus etc. In the Ogdensburg 

 area the representation of the Beekmantown above the 

 Tribes Hill has been called the Ogdensburg dolomite 

 (Cushing '16). There are 120 feet of this limestone rep- 

 resenting only the upper beds of the Champlain area 

 (Middle and Upper Canadian). 



