468 PALEONTOLOGY OF ILLINOIS. 



along the middle above, where they form the bottom of the 

 ambulacra! furrows; further down, the pore pieces close in 

 so as nearly or quite to cover the lancet pieces. Openings 

 usually called ovarian apertures, in the form of distinct 

 elongated slits, widest at the upper end, and extending down 

 apparently three-fourths the length of the pseudo-ambu- 

 lacra so very close to the margins of the latter as scarcely 

 to leave more than a very thin intervening space above, 

 and apparently none below. Central hiatus very small, 

 and doubtless covered by minute plates when entire. Sur- 

 face distinctly ornamented with very regular, wel] denned 

 striae running parallel to the upper margins of the basal 

 pieces and to the inferior and lateral margins of the radials. 

 Along the margins of the pseudo-ambulacral areas, narrow, 

 slightly flattened spaces are seen extending up the surface 

 of the radial pieces, and corresponding to rather broad, 

 deep furrows seen occupying the same positions on the last 

 described species. (Column and pinnulse unknown.) 

 Hight, 0.60 inch ; breadth about 0.50 inch. 



This species, although agreeing with the last in the important char- 

 acter distinguishing it from Pentremites and Cadaster, differs so mate- 

 rially in form and other details as to render a comparison unnecessary. 

 In general form, it much more nearly resembles true Pentremites than the 

 typical Codonites stelUformis does. 



Locality and position Lower division of the Burlington group of the 

 Lower Carboniferous, at Burlington, Iowa. Mr. WACHSMTJTH'S collec- 

 tion. 



GENUS GKAXATOCKI1STJS, Troost. 

 GKANATOCKLNTTS MELONOIDES, M. and W. 



PL 9, rig. i. 



Granatocrinus melonoides, MEEK and WOBTHEN. Proceed. A cad. Nat. Sci., Phila., 1869, p. 88. 



BODY rather under medium size, globose in form. Base 

 very small, nearly even with the prominent lower extremi- 

 ties of the pseudo-ambulacral areas. Kadial pieces nearly 



