1881.] NATURAL SCIENCES OF PHILADELPHIA. 287 



185S. Agaricocr. stellatus Hall. Geol. Rep. Iowa, i, pt. ii, p. oB-t. Upper Burling- 

 ton limest. — Burlington, Iowa. 



1850. Agaricocr. Whitfieldi Troost. List. Crin. Tenn. ; Hall, 1858, Geol. Rep. Iowa, i, 

 pt. ii, p. 621; Supp. Iowa, Rep. I860, PL .3, fig. 5 ; Meek and AVorthen, Geol. 

 Rep. 111., vol. V, p. 499, PI. 12, fig. 1, and PI. 15, fig. 8. Keokuk limest. 

 Green Co., 111. 



1858. Agaricocr. Wortheni Hall. Gtol. Rep. Iowa, i, pt. ii, p. 619, PJ. 14, fig. 1; 

 Wachsm. and Spr., 1878, Proc. Acad. Nat. Sci. Phila., p. 240. Upper por- 

 tions of Keokuk limest. Iowa, Illinois and Missouri. 



Subgenus ALLOPROSALLOCRINUS Lyon and Cass. 



1860. Lyon and Casseday. Am. Acad. Arts and Sci., vol. v, p. 29. 

 1866. Shumard. Cat. Pal. Foss, N. Amer., pt. i. p. 353. 

 1873, Meek and Worth, (in part). Geol. Rep. 111., vol. v, p. 368, 

 1879. Zittel. Handbuch der Palaiontologie, i, p. 370. (Not Meek and 

 Worth., 1865, Proc. Acad. Nat. Sci. Phila., p. 164). 

 Syn. Conocrinus Troost, 1850. List of Crin. Tenn. (not defined), 



L^^on and Casseda}" in defining the genus Alloprosallocrinus 

 placed under it two species : their type A. conicus and A. dejjressus^ 

 the latter probably an Agaricocrinus. With this genus Allopro- 

 sallocrinus has close affinities ; it differs, however, in having an 

 almost central anal tube and not a lateral opening through the 

 vault. The tube which extends from an elevated tuberculous dome, 

 gives to A. conicus a superficial resemblance to some of the later 

 forms of Batocrinus, and this induced Meek and Worthen to place 

 Lj^on's genus a mere subgenus under the other. 



Meek and Worthen added a new species, but we doubt from 

 their description of A. euconus, if they correctl}' identified Lj'on's 

 typical form, or the}- would have found the two species to be, super- 

 ficiall}' at least, veiy distinct. The foi'm of the plates in the calyx, 

 and particularly- of those near the arm regions, is in Meek and 

 Worthen's species like in Batocrinus, hut in A. conicus almost 

 identical with Agaricocrinus. We refer the former to Batocrinus, 

 and place Alloprosallocrinus subgenericallj' under Agaricocrinus. 

 Lyon and Cassedaj' describe the primarj' radials as being com- 

 posed of only 2X5 pieces. This is sometimes abnormall}- the 

 case, but there are always as a rule three plates in each ray, of 

 which the second are exceedingly short, linear and easil}- over- 

 looked. 



Amended Diagnosis. — General form turbinate ; calj'^x truncate, 

 slightl}' convex. Basals and primarj^ radials like those of 

 Agaricocrinus .^^ with 2 X 10 narrow secondary radials succeeding 



