298 Neio Species of Crinoidea from the 



stone, Burlington, Iowa. Collection of Rev. W. H. Bar- 

 ris. 



Cyathocrmiis Lyoni (n. s.). Calyx massive, broadly 

 cyathiform, about once and a half as wide as high. Basal 

 plates very small, the angles only projecting beyond the 

 summit of the column. Sub-radial plates very large, 

 higher than wide, three hexagonal and two heptagonal. 

 First radial plates very large, nearly twice as wide as 

 high ; the upper lateral sides being comparatively long^ 

 and the articulating scar of moderate size, give a heptag- 

 onal outline ; the articulation occupies little more than 

 one third the width of the top of the plate. Second and 

 third radial plates quadrangular, wider than long; the sec- 

 ond shorter than the third. Fourth radial pentangular, 

 with short lateral margins, acutely angufar above. 



Arms long and slender, two from each ray, composed of 

 plates which are nearly as long as wide, slightly wedge- 

 form, throwing off' branchlets at intervals from opposite 

 sides. Towards the middle, in the length of the arm, the 

 branchlets are given off from every second plate on alter- 

 nate sides, the intermediate plate being smaller. A large 

 quadrangular anal plate is situated between two of the 

 sub-radials and the radial plate on the right hand side ; 

 the succeeding anal plates undeterminable. Column 

 round, of medium size, composed of thin alternating 

 plates. Surface smooth or finely granulose. 



This species differs from all others of the type in the 

 large anal plate intercalated obliquely below the radial 

 and resting on two sub-radials. It differs from C. Hoveyi 

 in the smaller basal plates, the larger sub-radials, in hav- 

 ing four instead of three plates in the radial series, with a 

 smaffer articulating scar, and in the longer and more slen- 

 der arms, which have no true bifurcations. 



Geological formation and locality. Keokuk limestone, 

 Crawfordsville, Indiana. Collection of Wabash College. 



