196 ORINOIDS. 



Calyx small, very broad at the base, slightly expanding^ 

 above, with plates smooth and sutures impressed ; basal disk 

 very low, nearly as wide as the greatest breadth of calyx; 

 radials almost rectangular. 



Horizon and locality. — Lower Carboniferous, Chouteau 

 limestone : Sedalia. 



Platycrinus absentivus (Miller). 



Plaiycrmus absentivus Miller, 1891 : Geol. Sur. Missouri, Bui. 4, p. 15, 

 pi. i, fig. 15. 



A form closely approaching P. pileiformis, but much 

 smaller and more delicate. 



Horizon and localities. — Lower Carboniferous, Chouteau 

 limestone : Sedalia. 



Platycrinus aequiternus (Miller). 



Platycrinus cequiternus Miller, 1891 : Geol. Sur. Missouri, Bui. 4, p. 14, 

 pi. i, fig. 13. 



Calyx somewhat resembling that of P. allophylus, but 

 spreading more rapidly and without the annulated base. 



Horizoii and localities. — Lower Carboniferous, Chouteaa 

 limestone : Sedalia. 



Platycrinus annosus Miller. 



Platycrinus annosus Miller, 1891: Geol. Sur. Missouri, Bui. 4, p. 14, pi. i, 

 fig. 12. 



Calyx like that of P. pileiformis, but much smaller. 

 Horizon and localities. — Lower Carboniferous, Chouteau 

 limestone : Sedalia. 



Platycrinus allophylus (Miller). 



Platycrinus allophylus Miller, 1891: Geol. Sur. Missouri, Bui. 4, p. 9, pi. 

 i, figs. 3-4. 



Calyx obconical, truncated and expanded below ; basals 

 high, with a more or less well-defined annulation around the 

 margin of the flattened truncation ; radials rather email, pro- 

 tuberant at the arm base; facets large ; surface smooth. Stem 

 rather stout. 



Horizon and localities — Lower Carboniferous, Chouteau 

 limestone: Sedalia. 



