NIAGARA FALLS AND VICINITY 137 



ance, somewhat resembling the convolutions of the intestine; those 

 of the last cycles short; all with papillate elevations or carinae on 

 the sides, giving in section a crenulate or echinate appearance. Dis- 

 sepiments present. Epitheca well developed. 



Enterolasma caliculus (Hall) (Fig. 29) Streptelasma 

 cali cuius Hall (1852. Pal. N. Y. 2:111, pi. 32) 



Distinguishing characters. Turbinate, oblique or curved, more 

 or less rapidly expanding' form; r- 



moderately deep cup; septa 20 to 



1 

 50, separated by a space of twice 



their width; well marked costal 



grooves which lie opposite both 



long and short septa; relatively thin 



, , , ... Fig. 29 Enterolasma oalieulus 



and smooth epitheca. 



Found rarely in the upper Clinton beds, and abundantly in the 

 lenses of limestone in the Clinton, the lower part of the Rochester 

 shales and the Bryozoan beds of these shales. Also in the same 

 shales at Lockport and farther east. 



Genus zaphrentis Rafinesque 



[Ely.: 'Ca, many; pprjv, diaphragm] 



(1820. Ann. des sci. phys. Brux. 5:234) 



Corallum simple, conic or turbinate, or conico-cylindric, with a 

 deep calyx, and well developed septa, the primary ones reaching to 

 the center. Dissepiments and tabulae occur, the latter usually well 

 developed. A deep fossula marks the abortion of one of the four 

 primary septa. Costae and a thin epitheca occur. 



Zaphrentis turbinata (Hall) (Fig. 30). Polydilasma tur- 

 binatum Hall (1852. Pal. N. Y. 2:112, pi. 32) 



Distinguishing characters. Form variable, usually short and tur- 

 binate ; calyx gradually deepening from margin halfway to the center 

 and then abruptly descending, almost vertically to a moderate depth ; 

 alternate septa terminating at point of sudden deepening of calyx, 

 others reaching to center; dissepiments slightly developed. 



Found in the Lockport limestone at Niagara(?) and Lockport, 

 where it occurs a few feet above the shale. 



