689 



Plat. 



{Figure of Platycrinus planus,) 





Ow. p. p. 



Platycrinus praematurus. Hall & Whitfield, in Pal. Ohio, 



Yol. 2, 1875, p 124, pi. 6, figs. 3, 4, gutta-percha casts ; 5, 6, in- 

 terval cast of calyx, basal and lateral views, basal plate sur- 

 face tuberculose ; general surface smooth. Note. Gutta-percha 

 casts of hollows left by dissolution of the crinoid are very 

 different from the natural casts of the interior of the body as 

 numerously found, viz : flattened or depressed spheres, pre- 

 serving only the suture lines bat showing none of the external 

 features except the shape of the plates. Niagara, Vh. 

 Platycrinus richfieldensis, H. & Whit. Pal. Ohio, Vol. 2, 



1875,p.l67,pl.ll,f. 

 1, very slightly re- 

 stored in drawing 

 the region of the 

 radial plates; cup- 

 plates smooth 

 even under a mod- 

 erate lens; small 

 column of alternate large and small joints; aspect of Dicho- 

 crinus^ but all first radial plates carry arms. Waverly. X. 





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