New Species of Crinoidea and other Fossils. 



207 



Fig. 2. 



^ 



formation, in the depressed anal, interradial and intersupraradial 



areas, and in the smaller and more numerous plates of these areas, 



which are also destitute of the stellate 



ridges which characterize those of 



that species. It also differs in having 



tlie arms becoming free and composed 



of small tentacula-bearing plates below 



the second bifurcation of the ray, 



although possessing the same number 



of arms. 



In G. decadactylits the body is 

 more robust and gibbous, the inter- 

 radial spaces are not depressed, and 

 the plates are marked by radiating Diagram illustrating the structure 



riageb , Ulb caiyx exuenub aoove ine reduced to the smallest possible size. The 

 second bifurcation of tlie ray, and P.I^^^^^s of the ray to beyond the secomlblfurca- 

 - , 111 tion are all polygonal, and present a strong 



the arms become tree only above that contrast to the corresponding portions of G. 

 • J J 9 Nealli. a represents the basal and subradial 



point. plates enlarged to two diameters to show 



Formation and locality. In shales ^^^ ^^"^^^ ^^'^^'• 

 of the Hudson-river group, near Lebanon, Ohio From Mr. J. Kelly 

 O'Neall. 



Fig. 3, 



Diagram of Glypt aster (inornaius) from the Niagara group, introduced to show the difierences 

 between this and the genus Glyptocrinus. In this diagram the basal plates are seen to be of much 

 larger size, and are visible beyond the circumference of the column ; Avhlle the anal area a is larger 

 than the interradial series, and is composed of a greater number of plates, the lower one of which 

 truncates the subradial ; while in the latter genus the areas are all similar to each other, and vary 

 but slightly in the number and arrangements of the plates composing them. 



Glyptocrinus parvus n. sp. 

 Plate 5, fig. 17. 

 Body small, narrow, turbinate to the bases of the free arms. Sub- 

 radial (basal) plates about equal in height and width ; the plates of 

 the radial series sub-equal, the first ones a little the largest. Rays 

 dividing on the third radial plate, and again on the second supra- 



