ARTICLE XVI. 



REMARKS ON THIRTEEN NEW SPECIES OP CIUNOIDEA FROM THE PALAEOZOIC ROCKS OF INDIANA, KENTUCKY, 



AND OHIO, AND A DESCRIPTION OF CERTAIN PECOLIARITIES IN THE STRUCTURE OF THE COLUMNS 



OF DOLATOCRINUS, AND THEIR ATTACHMENT TO THE BODY OF THE ANIMAL. 



BY SIDNEY S. LYON. 

 Kead, February 19, 1809. 



Thirty years have passed away since the collection was commenced which is now the 

 subject of this paper. 



The rocks outcropping at the water's edge along the Falls of the Ohio, have become 

 extensively known to geologists and collectors of fossils. 



One of these beds has become known as the (Olivanite bed) Nucleocrinus bed, or more 

 commonly as the Ilickorynut bed. The entire thickness of this bed, in the greatest 

 expansion observed, is about four feet ; from this thickness it diminishes to a knife-edge, 

 and at many localities it thins out entirely and disappears. 



This horizon is the place of Nucleocrinus Vemeuilli, Nucleocrinus angularis, Dolatocrinus 

 lucus, D. glyptus, Hall (if the identification made is correct), Mageslocrinus spinusolus, Po- 

 teriocrinus simplex, and Poteriocrinus cylindricus, Actinocrinus penta-spiinus, Actinocrinus 

 midticorula, of this paper; also three species referred to a new genus, Hadrocrinus, and 

 described in this paper. There have been found three or four other species not identified, 

 probably new. 



At the quarries on Bear Grass Creek, Jefferson County, Kentucky, the crinoidal bed 

 above referred to has become quite thin, or has entirely disappeared. Above its place is 

 a bed of hydraulic cement stone, from four to eighteen inches in thickness. At the foot 

 of the Falls of the Ohio, the cement bed has increased in thickness, and it is at this last- 

 named locality about nineteen feet thick. 



Succeeding the hydraulic beds is situated a bed of shaly limestone, from six to eight 

 feet thick, containing a large number of crinoidea, but none of those before enumerated 

 have been identified as occurring in it. In this last bed have been observed and identi- 

 fied, Dolatocrinus Troosii (Cocabiocrinus Troosti), Dolatocrinus liratus (C liratus), Dolato- 



