322 New Species of Crinoidea from the 



are visible beyond the basal cavity. Sub-radials of medium 

 size, wider than high, four hexagonal, and one, on the anal 

 side, large sub-heptagonal. First radials large, nearly as 

 wide again as high, sub-pentagonal, with the upper lateral 

 angles slightly truncated, upper margins concave. Second 

 radials short and broad, quadrangular, nearly three times 

 as wide as high, less wide than the first radials, but allow- 

 ing the upper margins of these to curve around their ends. 

 Third radials short and broad, wedge-form above, support- 

 ing an arm on each upper side. 



Arms bifurcating on the second plate, simple above, as 

 far as determined. Anal plates unknown. Surface finely 

 granulose, the granules confluent in places, appearing like 

 broken striEe. 



This species differs from M. Konincki (1st Supp. Iowa 

 Geol. Rep. p. 69) in the less distinctly globose body, its 

 calyx being broader and more regularly expanding. The 

 basal portion of that species is not impressed, and the 

 basal plates form a pentagon with straight sides, making 

 the sub-radials pentagonal instead of hexagonal ; the arms 

 also are strongly curved sidewise, while in this species they 

 are nearly straight. The plates of the arms and radial 

 series are likewise different in form. 



Geological formation and locality. Burlington lime- 

 stone, Burlington, Iowa. Collection of B. J. Hall. 



Rhodocrinus Barrisi (n. s.). Body small, sub-globose, 

 base somewhat deeply impressed. Basal plates small, 

 partially concealed by the column attachment. Sub- 

 radials proportionally large, hexagonal, their lower ends 

 forming the sides of the basal cavity. First radial plates 

 sub-heptagonal, much smaller than the sub-radials, widest 

 below. Second radials quadrangular and hexagonal, one 

 fourth as large as the first radials. Third radial plates 

 minute, sub-pentagonal, wedge-form above, and suj)i)orting 

 on each side a series of brachial plates. Interradial series 



