342 PROCEEDINGS OF THE ACADEMY OP [1879. 



F. DECADOCRINUS W. & Spr. 

 (Jixac number of ten ; xp~vov a lily.) 



Arms always ten in number. Calyx depressed. Shallow bowl 

 or saucer-shaped. Underbasals small, frequently hidden from 

 view in the concave base. Form of radials and brachials as in the 

 preceding group, the latter plates simple or compound. Arms 

 composed of arigular wedge-form joints, zigzag, with the longer 

 sides alternating and projecting so as to support short rounded 

 pinnule, which have the appearance of armlets. Column more or 

 less pentangular. 



a. Species with a Single Brachial. 



*1865. Poteriocrinus (Decadocrinus) Bayensis Meek & Worthen. (Scaphiocr. 



Bayensis.) Proc. Acad. Nat. Sci. Phil., p. 157; Geol. Rep. 111., vol. v. p. 



550, pi, 20, fig. 2. Chester liraest. Subcarb. Illinois. 

 *1S70. Pot. (Decadocr.) depressus Meek & Worthen. (Scaphiocr. depressus.) 



Proc. Acad. Nat. Sci. Phil., p. 27 ; Geol. Rep. 111., vol. v. pi. 14, fig. 8. 



Keokuk limest. Subcarb Crawfordsville, Ind. 

 *1869. Pot. (Decadocr.) fiscellus Meek & Worthen. (Scaphiocr. fiscellus.) 



Proc. Acad. Nat. Sei. Phil., p. 141; Geol. Rep. 111., vol. v. p. 423, pi. 1, 



fig. 3. Lower Burl, limest. Subcarb. Burlington, Iowa. 

 *1861. Pot. (Decadocr.) Halli Hull. (Scaphiocr. Halli.) Desc. New Pal. Crin., 



p. 7; Bost. Journ. Nat. Hist., p. 308. Upper Burl, limest. Subcarb. Bur- 

 lington, Iowa. 

 *1864. Pot. (Decadocr.) lyriope Hall. (Scaphiocr. lyriope.) 17th Rep. N. Y. 



St. Cab., p. 58; Geol. Surv. Ohio, Pal., vol. ii. p. 175, pi. 12, fig. 10. Wa- 



verly Gr. Subcarb. Richfield, Ohio. 

 1864. Pot. (Decadocr.) pleias Hall. 17th Rep. N. Y. St. Col., p. 141; Geol. Surv. 



Ohio, Pal., vol. ii. p. 173. Waverly Gr. Subcarb. Richfield, Ohio. 

 *1869. Por. (Decadocr.) Stimpsoni Lyon. (Zeacr. Stimpsoni.) Trans. Am. 



Philos. Soc, Phil., p. 465, pi. 27, fig. m, m 1. Subcarb. Kentucky. 



b. Species with More than one Brachial. 



*1864. Pot. (Decadocr.) aegina Hall. (Saphiocr. eegina.) 17th Rep. N/ Y. St. 



Cab., p. 57; Geol. Rep. Ohio, Pal., ii. p. 174, pi. 12, figs. 11, 12. Waverly 



Gr. Subcarb. Richfield, Ohio. 

 1861. Pot. (Decadocr.) diffusus Hall. 15th Rep. N. Y. St. Cab., p. 121. Hamil- 

 ton Gr. Devonian. Ontario Co., New York. 

 *1S63. Pot. (Decadocr.) gracilior F. Roemer. (Cyathocr. gracilior.) Dunker's 



Palaeontologr., vol. ix. p. 149, pi. 29, fig. 1 ; pi. 25, figs. 8, 10. Dachschiefer. 



Grauwacke. Bundenbach, Germany. 

 *1869. Pot. (Decadocr.) juvenis Meek & Worthen. (Scaphiocr. juvenis.) Proc. 



Acad. Nat. Sci. Phil., p. 146 ; Geol. Rep. 111., vol. v., p. 417, pi. 2, fig. 8. 



Lower Burl, limest. Subcarb. Burlington, Iowa. 

 1861. Pot. (Decadocr.) nycteus Hall. 15th Rep. N. Y. St. Cab., p. 120. Hamilton 



Gr. Devonian. Ontario Co., N. Y. 



