302 Neio Species of Crinoidea from the 



This species resembles the last in its large inflated pro- 

 boscis and the general expression of the calyx and arms, 

 but in detail it is quite distinct. In this species the second 

 radials are uniformly smaller than the first, and are entirely 

 separated from each other, while in that species the sec- 

 ond radials are larger than the first, and united at their 

 lateral margins ; and the arm plates are more distinctly 

 wedge-form, and not extended across as in that species. 

 But the most striking difterence is in the proboscis, which 

 is composed of large plates in the lower part and smaller 

 in the upper, which is the reverse of the other species ; 

 and the inflated portion appears to have been sub-globose 

 instead of angular at the greatest expansion. 



Geological formation and locality. Burlington lime- 

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



Poteriocrinns fusiformis (n. s.). Calyx obconical, trun- 

 cate at base, very gradually expanding, the diameter of 

 the base being equal to one third and the top equal to 

 two thirds the height of the cup. Basal plates placed 

 upright on the top of the column, pentagonal, height equal 

 to once and a half the width, sides sub-parallel, obtusely 

 angular above. Sub-radial plates much larger than the 

 basal plates, three hexagonal, two on the anal side hep- 

 tagonal and larger, height and width as three and two. 

 First radial plates comparatively small, less than one half 

 the size of the sub-radials, pentangular, wider than high, 

 supporting the first arm plates, which are long and narrow. 

 First anal plate pentagonal, a little smaller than the first 

 radial plate adjoining; the remaining anal plates and the 

 arms above the first plates unknown. 



Surface of plates smooth. Column smooth, round, 

 rapidly tapering downwards, composed of thin, equal 

 plates. 



The body of this species has some resemblance to 

 Pofrrincrinna Missouriensis, but is smaller and less rap- 



