G. H. Gordon — Keokuk Beds at Keokuk. 299 



dently allying this stratum with the crinoid bed at Craw- 

 fordsville, Ind., while the resemblance is still further enhanced 

 by the lithological character of the stratum. At the above 

 locality there are twenty-five feet of fossiliferous shale under- 

 lying the crinoid beds and followed downward by two hundred 

 feet of limstone and shale. * Now while at Crawfordsville the 

 beds are marked by the Poteriocrinidse, at Keokuk the fauna 

 of the lower division is essentially Actinocrinoidal in aspect. 

 The most common forms occurring in the lower division at 

 Keokuk, viz : Batocrinus NashvUlce, B. biiitrbinatus, Acti- 

 noorinus pernodosus and Agaricocrinus Wortheni, are absent 

 at Crawfordsville, while even the ubiquitous Agaricocrinus 

 Americanus is not recognized in the corrected lists of fossils 

 from that locality. 



We are disposed therefore to consider it as not improbable 

 that the crinoid beds at Crawfordsville and the associated shale 

 are the stratigraphical equivalent of the Geode bed and its 

 associated layers at Keokuk. 



The second crinoid bed is known as the Dorycrinus Bed, 

 from the abundance of a single species of that genus, D. Mis- 

 sissijyjpiensis. 



The interest attaching to these beds centers largely in their 

 Radiates of which the Crinoidea are the most prominent. The 

 following table gives approximately the genera and number of 

 species and their relations at Keokuk and Crawfordsville : 



Genera. 

 Actitiocrinus, 

 Agaricocrinus, 

 Batocrinus, 

 Barrycrinus, 

 Calceocrinus, 

 Catillocrinus, 

 Cyathocrinus, 

 Decadocrinus, 

 Dichocrinus, 

 Dorycrinus, 

 Eretmocrinus, 

 Euciadocrinus, 

 Eupachycrinus, 

 Eorbesiocrinus, 

 Goniasteroidocrinus, 

 Graph locrinus, 

 Onychocrinus, 

 Parisocrinus, 

 Platycrinus, 

 Poteriocrinus, 

 Rhodocrinus, 

 Scaphiocrinus, 



Scytalocrinus, 4 3 



Stemmatocrinus, 1 



* Beachler, Am. Geol., vol. ii, p. 407. 



Total 



At 



At Craw- 





Species. 



Keokuk. 



lordsville. 



Species common. 



6 



5 







6 



2 



1 





13 



7 



2 



B. Indianensis. 



L5 



9 



2 





4 



2 



1 





2 





1 





n 



2 



5 





2 



1 



1 





5 



3 



2 



D. ficus. 



4 



4 







5 



3 







1 



1 







1 



1 







2 



1 



1 



F. Wortheni. 



2 



1 



I 





o 



1 



2 



0. ramulosus. 



1 



1 







5 



4 



1 



P. liemisphericu; 



3 



1 



1 





1 



1 







16 



12 



4 





