DESCRIPTION^ OF NEW SPECIES OF FOSSILS 



FROM THE 



HUDSpN RIVER GROUP, IN THE VICINITY OF CINCINNATI, OHIO. 



By JAMES HALL. 



In ISTovember, 1866, some advance sheets of the Twentieth Report 

 on the State Cabinet of Natural History were published, containing 

 descriptions of new species of Crinoidea, and other fossils. Owing 

 to the delay in completing the plates for illnstraling tlie paper, it was 

 omitted from its place in the final publication of the Eeport, an 

 explanation of this fact appearing in the proper place. f 



In that paper I published a description of the Genus Lichenocri- 

 Nus from specimens then in my possession. Soon afterwards I 

 received from Mr. C. B. Dyer, of Cincinnati, other specimens, which 

 seemed sufficient to disprove the existence of a proboscis which had 

 been described as cliaracteristic of the genus. In the specimens first 

 described the portions of this appendage preserved w^ere crushed, and 

 not more than lialf a line in length, consisting of a series of small 

 plates interlocking at their lateral margins after the manner of such 

 organs in other crinoids. In some specimens, under later examina- 

 tion, this appendage has a length of several inches, and in others it is 

 broken off at difi*erent distances from the body. It is composed of 

 distinct plates scarcely interlocking at their lateral margins, but 

 assuming the cliaracter of a column or stem. 



The adhering face of the criuoid, which lias been seen in several 

 specimens, presents a striated surface, and is composed of a series of 

 fine radiating lamellse with narrow interstices. These vertical lamel- 

 Ige reach to the inner surface of the exterior plates, and the whole 

 presents much the aspect of a shallow cup surrounded by crinoidal 

 plates and filled with a finely radiating coral. We may imagine that 

 the spaces between these lamellse have been occupied by slender fleshy 

 tentacula. The fossil is usually found adhering by the striated or 

 lamellose face to shells or other organic bodies ; and if we suppose 

 this part to have been the place of lodgment of the viscera, it pre- 

 sents a very anomalous condition, and we can scarcely believe that 

 the position in which we find it is the normal one. From the pecu- 

 liar construction of this disc, it might be suggested that the animal 

 was capable of thus attaching itself temporarily and removin'g at 

 will. 



* Published October, 1871, as advance sheets of the State Museum Report. 

 tThe paper appears in the present Report, page 205. 



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