208 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.41. 



western Illinois, eastern Iowa, and Missouri, with its long and quiet 

 deposition of strata, was the chief habitat and center of distribution 

 of the crinoids during that epoch; and that the occurrences in 

 Indiana, Kentucky, and Tennessee represent migrations involving 

 only part of the species, repeatedly interrupted and renewed, as evi- 

 denced by the frequent bands of crinoidal limestone with muddy 

 clays and shales between. Wliat name should be attached to these 

 beds would probably be a matter of contention between the geolo- 

 gists of the different States. I am not so much concerned about 

 that, so long as the facts are understood, and willingly leave it to 

 those in authority to settle. But I think I may say with confidence 

 that the name will not be Keokuk. 



