188. CONTRIBUTION TO 



bly three. Shortly after becoming free, one arm bifurcates making six arms 

 to the series or thirty in all, perhaps. At half their height the arms bifurcate 

 again. The basal plates form a rim about the column, the three upper joints 

 of which are strongly ridged. 



The ventral disk is quite as deep as the dorsal cup and the plates are con- 

 spicuously nodose, but without ornamentation. 



The ventral tube, three-fourths of an inch of which is preserved on the 

 type specimen, is hardly strong with nodose and spinose plates. The pinnies 

 are rather long. 



The whole body is somewhat flattened or crushed in at the anal interra- 

 dius in the calyx and extending along the vault nearly to the anal tube base. 



We should be glad to place this crinoid under one or the other of Wachs- 

 muth & Springer's species A. multiramosus or A. magniiicus, but it differs 

 from both in so many details that we are constrained to erect a new variety for 

 its reception. First, it differs from both in plate ornamentation ; second, from 

 A. multiramosus in the much greater height of the ventral disk, that of the 

 latter species being from one-fourth to one-third the height of the calyx, while 

 in our species it is fully as high as the dorsal cup. From A. magniiicus it dif- 

 fers in its shallower dorsal cup and the basal rim wanting in the latter species. 

 From both species it differs in the much greater height of the free arm bifur- 

 cation. 



With both, it agrees in the number of arms and lack of lobed character of 

 arm bases. 



This beautiful crinoid comes from the Keokuk Limestone of Washington, 

 county, Ind., and belongs to the cabinet of Mr, G. K. Greene. 



BATOCRINUS SPERGENENSIS, Miller, Rowley. 



Plate 57. Figs. 3, 4. 



The specimen we have figured is not quite so much depressed as Miller's 

 type but preserves the plate ornamentation which consists of low irregularly 

 arranged elevations and depressions hardly noticeable to the eye, presenting a 

 somewhat pitted appearance. The outer edges of the basal plates are raised 

 into a rounded ring-like elevation. 



The ventral disk is composed of numerous convex plates. 

 The proboscis is not strong and excentrically located. 



