24 I.ARVIIORM CRINOIDS 



quarry about two miles south of Fairmont, Vermilion County, Illinois. The 

 exact position of this limestone with regard to the standard Illionis section 

 is not definitely known but the horizon is not far from that of the Lonsdale 

 limestone" although it may he somewhat higher. 



Kallimorpiiocrinus pocili.us J. M. Weller, n. sp. 



Plate II, figs, la-d 



Description. — The calyx is small, the greatest diameter being somewhat 

 less than the height which is 1.48 mm. in the holotype. The horizontal outline 

 is distinctly five-lobed owing to the convex form of the radials whose lateral 

 slopes form broad, more or less deep concavities along the centers of which 

 lie the sutures. The radials form about seven-ninths, and the underlying 

 base and the crowning orals each form about one-ninth of the total height. 

 Beneath the base in some of the specimens occurs a thin stem-joint firmly 

 attached to the calyx. 



The basals are firmly anchylosed into a low basal disc which slopes gently 

 outward to the slightly excavated suture separating it from the radials. It is 

 nearly circular in outline but is beveled above by five inclined planes upon 

 which the radials rest, thus giving it a somewhat pentagonal appearance. The 

 stem facet occupies the whole lower surface of the basal disc. It is nearly 

 circular, large, with a diameter only slightly less than half that of the calyx, 

 and was probably pierced by a single central opening. 



The radials are subrectangular in outline, nearly twice as high as wide, 

 and approximately equal in size. Their outer surfaces are convex both hori- 

 zontally and vertically. The vertical convexity occurs chiefly in the lower 

 half and thus the greatest diameter of the calyx occurs at about mid-height. 

 The horizontal convexity increases rapidly from the lower edge of the radials 

 upward to about the middle, beyond which it remains fairly constant. The 

 upper corners of the radials are somewhat notched forming shallow concave 

 grooves sloping upward and inward to the orals. 



Each radial hears upon its distal surface an articular facet for the re- 

 ception of an arm. These do not extend over quite all the width of the radials 

 but are separated from each other by the shallow concave grooves mentioned 

 above. There is more variation in the size of the articular processes than 

 in any other part of this crinoid. Commonly that of the anterior radial is the 

 smallest and those of the posterior radials largest but the gradations in size 

 are not at all regular. 



The orals form a rather flat-topped crown rising sharply above the 

 radials. In diameter and height the crown is nearly equal to the basal disc 

 and is on the whole less conspicuous in this than in most of the other species 

 here described. The oral plates are nearly uniform in size, the posterior one 



In the Peoria district, the Lonsdale limestone occurs about 120 feet above coal Xo. 6. 



