38 



Cincinnati Society of Natural History. 



Basal plates more full}' developed than tl^ are in G. decadactylus. 

 The two ridges extending below, from the center of the first radial s, 

 and uniting with the ridges on the surface ot the basals, rapidly ex- 

 pand, as they do in G. angularis. The first, second, and third radi- 

 als are much like the same plates in G. decadactylus, except the radial 

 ridge is smaller, and the plates are wider in proportion to their length. 



There are three secondary radials in each series, which are a little 

 smaller than the primary radials. The upper sloping sides of the 

 third secondary radials support six or eight brachial plates before the 

 arms become free. The free arms are directly continued from the 

 brachial plates without another bifurcation. There are twenty long, 

 round arms, composed of cuneiform plates, and having long, slender 

 pinnules. The column is round, and composed of alternately thicker 

 and thinner plates. The surface of the plates is deepty sculptured. 

 The number of plates in the inter radial areas has not been deter- 

 mined. <r 



This species is founded upon two specimens from the collection of 

 I. H. Harris, Esq., of Waynesville, Ohio. They were found in the 

 upper part of the Hudson River Group, in that vicinity. 



Anomalocrinus. 



Plate I., figs. 3 and 3a, roots and lower part of the columns; fig. 3b, part of a column longi- 

 tudinally divided into fifteen parts; 3c, part of a column longitudinally divided into twenty 

 parts; fig. 3d, interior view of part of a column; fig. 3e, transverse section, showing the 

 size of the central opening. 



The column of this genus was almost, or quite, unknown to Prof. 

 Meek, and as Wachsmuth and Springer, in their Revision of the Palceo- 

 crinoidai, p. 73, have copied only what Prof. Meek said, in Ohio Pal., 

 vol. i., p. 18, where he was evidently describing the base and lower part 

 of the column of a Heterocrinus, as I pointed out in the Quarterly 

 Journal of Science eight } r ears ago, instead of the Anomalocrinus, I 

 have deemed it important to illustrate and describe some of the parts 

 of the column and its roots. If these parts are of special morpho- 

 logical importance, as they seem to be, because constituting so much the 

 larger part of the crinoicl, and possessing such complicated and vari- 

 able structure, then the family affinities of this genus may not be 

 correctly ascertained. Instead of having a flat base as in Hetero- 

 crinus, it possessed roots that enabled it to cling to several stems of 

 a branching coral. The roots are not numerous, as in Eucalyptocri- 

 nus, but still there are several springing from each base, that has fallen 

 under my observation. It seems to have grown in clusters, with 



