342 PALAEONTOLOGY OF ILLINOIS. 



ACTIXOCRLNTTES. Section (a). 



ACTINOCKINITES PENICILLUS, M. aild W. 



PL 8, fig. 2* 

 Actinocrinus penicittw, MEEK and WORTHKX. Proceed. A.cad. Nat. Sci., Phila., 1869, p. 155. 



BODY small, inversely campanulate, or with sides ex- 

 panding rapidly from the truncated base to the secondary 

 radials, which with the brachial pieces cnrve a little out- 

 ward. Base much depressed, or about four times as wide 

 as high, broadly truncated, and but slightly concave below; 

 margin more or less expanded horizontally, and deeply 

 notched at the sutures. First radial plates comparatively 

 rather large, and about twice as wide as high. Second ra- 

 dials near half as large as the first, about twice as wide as 

 high. Third radials a little larger than the second, wider 

 than long, and pentagonal in form, the lateral margins 

 being short, each supporting on each of its superior sloping 

 sides a secondary radial of about its own size, which in its 

 turn supports two free arms". 



Anal pieces unknown above the second range ; first one 

 smaller (particularly narrower) than the first radials, and 

 supporting two others of its own size in the next range. 

 Interradial pieces three to five in each space ; first one as 

 large as the second radials, hexagonal in form, and bearing 

 upon its upper sloping sides two smaller pieces, above which 

 there is generally one or two minute pieces. 



Arms free from their origin on the secondary radials, 

 and composed below of slender rounded pieces, the first of 

 which is about twice as long as wide, and more or less con- 

 stricted in the middle ; beyond this the lateral arm on each 

 side of each ray is simple, with its second piece like the 

 first, and followed by two or three other shorter wedge- 

 formed pieces, before passing into a double series of small, 

 alternately arranged pieces. Inner arms of each ray bifur- 

 cating on the first piece, and one of the subdivisions in one 



