NIAGARA FALLS AND VICINITY 155 



with Eucalyptocrinus fragments and other crinoids, as well 



as other fossils. 



Stephanocrhms gemmiformis Hall (Fig. 49) (1852. Pal. N. Y . 



2:215. pi. 48) 



Distinguishing characters. Sharply 



triangular base; rapidly enlarging 



1-, calyx, which is rotund in the middle 



and slightlv contracted toward the sum- 



""• "■ ' . 



mit. "L pper margin of radials scarcely 



\_^ ■ 



depressed or excavated; granular non- 

 Fig. 49 stephanocrinus g^miformis marinate surface of plates ; slightly con- 



"with analysis of ealvx . . 



verging coronal processes. 

 Found in the Rochester shale at Lockport (Hall). Probably also 

 at Xiagara. 



Order cj^^l^^ratta. Wachsmuth & Springer 

 Genus thysanocrinus Hall 

 [Ety. : duaavbs, fringe; xpivov, lily] 

 (1852. Fal. N. Y. 2:188) 



Calyx deep, with a dicyclic base. Infrabasals and basals five 

 ■each, the former pentagonal, the latter generally hexagonal. Radials 





r 





Fig. 50 Thysanocrinus liliiformis with analysis of calyx 



five, hexagonal, laterally in contact, except at the azygous side, where 

 they are separated by an anal plate which is succeeded by three in- 



