350 Glyptocrinus Fornshelli. 



squares, rectangles, rhomboids, etc., or forming triangles ; their an- 

 gles being situated in the central or subcentral points of the pieces, 

 or at their junction, making it the most beautifully sculptured criuoid 

 known to the Cincinnati Group. 



The arms begin to rise on the third secondary radial and become 

 free on leaving the fifth, without a bifurcation. They rise vertically 

 from the last attached brachial piece, and consist of a series of round 

 wedge-shaped pieces, each of which supports a pinnule. They bifur- 

 cate on the twelfth piece from the third secondary radial, and again 

 and again bifurcate from the twentieth to the fortieth piece. They are 

 long, round, and smooth upon the outside. The pinnules are long and 

 very closely arranged along the inner lateral margins of the arms ; 

 they are composed of joints four or five times as long as wide. The 

 long, smooth arms, their frequent subdivisions, and the long, dense 

 jnnnules add very much to the exquisite beauty of this species. 



The column is of full average size, compared with that of other 

 species of the genus. It is sharply pentagonal and composed of alter- 

 nately thicker and thinner pieces, the former of which project very 

 slightly beyond the others ; the perforation is distinctly pentagonal, 

 but it is surrounded with a circular depression in each plate, which 

 gives the column the appearance of being round and encased with 

 pentagonal rings. In exposed and weather-worn plates the circular 

 piece falls out, which has led some, on looking at detached plates, to 

 suppose the perforation to be round. 



Looking at this species from any point of view, our interest is at once 

 excited. It is remarkable in the structure of its column, and this 

 becomes more worthy of observation, when we reflect, that it is the 

 only species in this genus having its column sharply pentagonal. It 

 sends up its free arms above the cup, without a bifurcation, which is 

 strikingly in contrast with G. decadactylus and G. dyeri. It possesses 

 great beauty, being the handsomest fossil ever found in the Cincinnati 

 Group, if, indeed, it is not the most exquisite ever found in the whole 

 range of the Lower Silurian rocks of Europe and America. And, too, 

 it is not a little remarkable that it should have remained unearthed 

 and unknown through all the years of toil and search which this 

 locality has undergone, and finally be discovered, within the past sixty 

 days, by a young collector, in no inconsiderable abundance, in com- 

 pressed masses, forming almost entire slabs or strata of rocks. 



The specific name is given in honor of the discoverer, F. L. Forn - 

 shell, Esq., of Morrow, Ohio, who also furnished the specimen for 

 illustration and description in this Journal. It was found in a branch 

 of Todd's fork of the Miami, a few miles east of Morrow, in the upper 



