ORINOIDS. 179 



A medium-sized form with slender arms and almost gla- 

 brate calyx. 



Horizon and localities. — Lower Carboniferous, Keokuk 

 limestone: Boonville. 



Batocrinus aequalis (Hall). 



Aciinocrinus cequalis Hall, 1858: Geol. Iowa, vol. I, p. 592, pi. xi, tigs. 4a-b. 



Aciinosrinus doris Hall, 18G1 : Desc. New Sp. Crinoida, p 15. 



Batoo'inus cequalis Meek & Worthen, 1873: Geol. Sur. Illinois, vol.V, p. 



367. 

 Batocrinus doris Meek & Worthen, 1873: Geol. Sur. Illinois, vol. V, p. 673. 



Calyx subglobose, with the arms springing from the equa- 

 torial region. Basals three, of equal size. Radials large, 

 about as high as wide; first costals quite small, quadrangular, 

 much wider than high; second costals somewhat larger than 

 the first, pentangular; subsequent orders of calyx brachials 

 about the same size as the second costals. Arms short, 

 biserial; pinnules, slender. Anal plate like the radials and in 

 the same circlet, with three pieces in the second row. Inter- 

 radials usually about three in number, the first very much larger 

 than the others. Ventral side hemispherical, made up of large 

 ossicles, the orals well defined ; anal tube very long, extending 

 beyond the ends of the arms. Surface of calyx plates quite 

 convex but not otherwise ornamented. Stem circular in cross- 

 section; axial canal pentangular. 



Horizon and localities Lower Carboniferous, Lower Bur- 

 lington limestone : Hannibal, Louisiana, Sedalia. 



Batocrinus clypeatus (Hall). 



Aciinocrinus clypeatus Hall, 1860: Geol. Iowa, vol. I, Supp., p. 12, pi. iii, 



fig. 12. 

 Aciinocrinus inornatus Hall, 1860: Geol. Iowa, vol. I, Supp., p. 24. 

 Acdnocrinus papillaius Hall, 1860: Geol. Iowa, vol. I, Supp., p. 29, pi. 



iii, figs. 10-11, 

 Batocrinus clypeatus Meek & Worthen, 1866 



p. 150. 

 Batocrinus inornatus Meek & Worthen, 1873 



p. 367. 

 Batocrinus papillatus Meek & Worthen, 1873 



p. 367. 



Geol. Sur. Illinois, vol. II, 

 Geol. Sur. Illinois, vol. V, 

 Geol. Sur. Illinois, vol. V, 



