Carboniferous Rocks of the Mississippi Valley. 299 



Cyathocrinvs viminalis (n. s.). Body small, depressed- 

 sub-globose, nearly twice as wide as high ; the greatest 

 diameter at the top of the sub-radial plates. Basal plates 

 small, pentangular. Snb-radial plates proportionally large, 

 height and breadth nearly equal, hexagonal, except one 

 on the anal side, which is pentagonal and larger. First 

 radial plates sub-heptagonal, about equal to the sub- 

 radials, slightly inflected at the upper lateral margins; 

 articulating scar for the attachment of the arm small, less 

 than one half the width of the plate, moderately im- 

 pressed. 



First anal plate hexagonal, with very small upper lat- 

 eral faces, supporting three plates, the middle one much 

 the larger; form and number of plates above undetermin- 

 able. The anal area extends above in the form of a 

 short proboscis, reaching nearly half an inch above the 

 arm bases. 



Arms composed of a single series of short plates below 

 and longer ones above, bifurcating on the second or third 

 plate above the first radial plate ; the second and third 

 bifurcations are on the second or third plate above the 

 preceding. One of the armlets on each main division of 

 the ray bifurcates at some distance above its origin. The 

 branches of the arms at their bifurcations are strongly di- 

 verging. Column very small, round, and composed, at a 

 distance from the body, of strong, thick plates of equal 

 size. 



This species differs from C. divaricatus (Geol. Rep. 

 Iowa, pi. 10, fig. 5) in its much larger sub-radial plates, and 

 less strongly diverging arms, which also are composed of 

 more numerous plates. 



Geological formation and localitij. Burlington lime- 

 stone, Burlington, Iowa. Collection of C. A. White. 



