CRINOIDS. 163 



rather long, slender, biserial ; pinnules small. Interradials 

 several, the largest resting on the basals. Ventral side flattened, 

 composed of a large number of small plates ; anal opening sub- 

 central, a simple aperture. Surface of calyx plates smooth. 

 Column round. 



Horizon and looalities. — Lower Carboniferous, lower Bur- 

 lington limestone : Louisiana. 



Rhodocrinus whitei Hall. 



Rhodocrinus whitei Hall, 1861 : Desc. New Species Crinoids, p. 9. 

 Rhodocrmus whitei Hall, 1861: Bostoa Jour. Nat. Hist., vol. VII, p. 321. 



Calyx large, depressed, spherical; ventral side elevated 

 somewhat, with a short but prominent anal tube. Surface of 

 the plates of the dorsal cup very convex, nearly hemispheri- 

 cal; smooth. 



Horizon and localities. — Lower Carboniferous, lower Bur- 

 lington limestone : Springfield, Louisiana. 



Rhodocrinus wachsmuthi Hall. 

 Rhcdocrinus wachsmuthi Hall, 1861 : Desc. New Species Crinoids, p. 18. 



Calyx very similar to B.wortheni but readily distinguished, 

 among other differences, by the deep, basal concavity, which 

 is slightly larger than the stem. 



Horizon and locality — Lower Carboniferous, lower Bur- 

 lington limestone : Louisiana. 



Rhodocrinus coxanus Worthen. 



Plate xxii, flg. 3. 

 i^AorfocHnws coa;anMS Worthen, 1882 : Illinois State Mus. Nat. Hi8t., Bui, 1, 



p. 30. 

 Rhodocrinus coxanus Worthen, 1883: Geol, Sur. Illinois, vol. VII, p. 305, 



pi. xxviii, fig. 7. 

 Rhodocrinus poly dacty Ills Worthen, 1883: Geol, Sur. Illinois, vol. VII, p. 



305, pi xxvii, fig. 5. 

 Rhodocrinus parvus Miller, 1891: Geol. Sur. Missouri, Bui. 4, p. 89, pi. v, 



figs. 8-9. 



Calyx of medium size, subglobose ; plates ornamented by 

 well-defined ridges radiating from the center of each piece to 

 the center of adjoining plates. Arras rather short, four to six 

 to the ray. 



Horizon and localities — Lower Carboniferous, Keokuk 

 limestone : Boonville ( Cooper county ) ; Keokuk ( Iowa ). 



