290 Neio Species of Crinuidea from the 



plates a little longer than their width at top, and very 

 gradually expanding from the lower margins ; articulating 

 scar narrow, occupying not more than one third the entire 

 width of the plate at the summit. Sub-brachial plates 

 two, very small, the first one quadrangular, the second 

 pentagonal, and bifurcating with very short lateral mar- 

 gins. 



The first arm plates longer than wide, and the arms ap- 

 parently bifurcating on the second plate above ; the plates 

 in the upper part of the arms very short. Column round 

 or round-oval above, consisting of alternating thicker and 

 thinner joints, which are irregularly disposed in the upper 

 part of the column, and more regularly alternating below. 

 Surface striato-punctate. 



This species has the form of D. elegans of De Koninck ; 

 but the sides are not as much curved, and the basal plates 

 are equal in length to the radials. The sides are straight- 

 er, and it is more distinctly obconical than D. Icevis ; and 

 in this respect it differs still more from D. ovatiis of 

 Owen. 



Geological formation and locality. Burlington lime- 

 stone, Burlington, Iowa. Collections of C. A. White and 

 B. J. Hall 



Dichocrinus liratiis (n. s.). Body abruptly spreading, 

 width a little more than twice the height, base broad ; the 

 columnar facet protruding and constricted above so as to 

 give a salient margin. Surface marked by strong radiat- 

 ing ridges, three on each plate, radiating to the lower lat- 

 eral angles of the radial and anal plates ; the spaces 

 between the radiating ridges are marked by concentric 

 nodes, or interrupted ridges arranged in concentric lines. 



The D. ovdtns of Owen is described as having a slight- 

 ly excavated facet for the attachment of the column, and 

 the surface marked by depressed granula^. The extremely 

 protruding base or column facet, which is constricted 



