216 



THE CRINOIDEA CAMERATA OF NORTH AMERICA, 



Geological and Geographical Distribution. 

 Number of known species. 



(Open figures indicate American, those marked ( ), European.) 



Formation. 



Rhodocrinid^. 



1 



CD 

 (D 



m 



V^ 

 O 

 ?-i 

 a; 

 m 



1 



zn 



American. 



Approximate 



European 



Equivalents. 



CO 



g 



1 



t 



03 



• 1—1 

 Ph 

 O 

 O 



a^ 



pi 



.9 



S 



CO 

 • r— t 



;h 

 O 

 O 



o 



1 



pi 



• rH 



o 

 o 



CO 



pi 



•r-l 

 •i-H 



1 



1 



i 



•a 



■ft 



CO 



:^ 



•I— 1 

 p-i 

 o 

 o 



s 



• 1— 1 



ft 



Keokuk. 











3 



2 













Upper Burlington. 









3 



(P) 



3 



(4) 













Lower Burlington. 









5 



4 













Kinderhook. 









3 













(1) 



Hamilton. 



Up. Devon. 









1 



1 



1 



(2) 









Upper Helderberg. 



Eifelbed. 







(2) 









(1) 



r— ( 



m 



Niagara. 



Wenlock. 

 Gotland. 













2 

 (1) 



(2) 



Hudson River. 





1 





















Trenton. 





1 



4 



2 



2 













(1) 



(1) 



Total species 54 j ,^ ^x 



2 



4 



15 



(7) 



10 



(4) 



1 

 (2) 



2 

 (1) 



(2) 



Remarhs. — When Roemer established the RhodocrinidaBj he was ac- 

 quainted only with the genus Ehodocrimis, in which he included also the 

 species which were afterwards referred to Ripidocrmus and Gilhertsocrimis. 

 He omitted Acanthocrinus, which he had himself proposed in 1850; probably 

 having discovered its identity with Rhodocrinus. 



The earlier French writers, d'Orbigny, de Koninck, Pictet, and Dujardin 

 and Hupe, placed Rhodocrinus with the Cyathocrinidae. 



The Rhodocrinidse of Zittel and de Loriol embrace Rhodocrinus, Olla- 

 crinuSy Acanthocrinus, Ripidocrinus, Hadrocrinus, Trybliocrinus^ and Thysano- 



* We have not seen Geinitz's description, but judge from Zittel (Handb. der Paleeont., Yol. L, p. 377) 

 that it is a doubtful or imperfectly defined genus. 



