LARVIFORM CRIXOIDS 



19 



which occupies its whole lower surface. The radials rest in scallops which 

 indent the upper and outer edge of the disc. 



The radials have a height equal to twice their mean width and are about 

 twice as wide above as below. They are extended into a median longitudinal 

 angulation which rises abruptly from the general curvature of the calyx at 

 the base of the radials and becomes increasingly prominent upward. The 

 lateral slopes from the angulations of adjoining radials meet at the suture 

 to form the sides of the calyx which becomes increasingly concave upward. 

 The angulations of the radials terminate above in slightly expanded knoblike 

 processes or are terminated by the beveling which leads upward to the arm 

 facets. The upper corners of the radials are r.ounded off and at their junc- 

 tures are concave depressions into which the orals extend. 



The articular facets of the radials are not well preserved in the single 

 known specimen of this species. 



The oral crown rises strongly above the radials and slightly overhangs 

 the dorsal cup interradiallv. The upper surface of each plate bears a broad 

 shallow depression and a small pustule marks the position of the madrepore 

 in the posterior radial. 



The surface of the calyx is marked by closely set, very minute pits which 

 probably indicate that the plates were originally porous. 



Remarks. — This species is distinguished from K. astrus by its stellate 

 outline which is unaccompanied by prominent radial knobs, and by its more 

 coarsely pitted surface. 



Occurrence. — The holotype was obtained from shale immediately under- 

 lying the Piasa limestone"' near the center of the NE. 34 sec. 25, T. 8 N., 

 R. 10 W., Jersey County, Illinois. 



Kallimorphocrinus lilius J. M. Weller, n sp. 

 Plate I, figs. 8a-b 



Description. — The height of the holotype, not including the stem joint 

 attached to its base, is .81 mm., which is slightly less than the greatest width. 

 A horizontal cross-section through the upper part of the radials is like a 

 five-rayed star with somewhat rounded points. The radials form about five- 

 eighths, the basal disc one-eighth, and the oral crown a little more than one- 

 fourth of the total height. 



The basal disc slopes outward and upward and supports the radials on 

 its upper beveled edges. Its flat circular basal facet is completely covered 

 by a stem joint. 



The radials are considerably wider above than below and their mean 

 width is somewhat greater than half their height. A longitudinal keel occu- 



5 The Piasa limestone occurs about 20 feet above the limestone cap-rock of the Herrin 

 ]\o. 6 coal. It is correlated with one of the limestones of the Henrietta formation of 

 Missouri and Kansas. 



