FOSSILS OF THE BURLIXGTOX GROUP. 417 



S< APHIOCRIXUS JUVEXIS, M. and W. 



fi a, fig. 8. 



Staphiocrintu jueenig, MEEK and WOBTHBS. Proceed. A cad. Sat ScL, Phila., 1869, p. 146. 



BODY small, expanding rather rapidly from the column, 

 or presenting a short, obconic form, with rather distinct 

 sinuses between the radial series; nearly twice as wide at 

 the top of the first radials as the hight to the same point. 

 Base small and short, or several times wider than high, 

 but projecting below the subradials, truncated about three- 

 fourths its breadth by the facet for the attachment of the 

 column. Basal pieces nearly twice as wide as long, and 

 pentagonal in form, but owing to the shortness of the lat- 

 eral margins, appearing nearly trigonal. Subradial pieces' 

 a little wider than long, three pentagonal, and two on the 

 anal side hexagonal (without counting a scarcely defined 

 angle at the middle of the under side of each). First radial 

 pieces of about the si/e of the subradials, generally wider 

 than long, and pentagonal in form. Second radials about 

 as long as wide, distinctly rounded on the dorsal side, and 

 quadrangular in outline. Third radials somewhat larger 

 than the second, more or less expanded at the upper end, 

 and rounded and contracted in the middle; each bearing 

 two arms on its superior sloping sides. 



Anal plates forming a double alternating series of five 

 or six pieces, as in the last: the lowest piece resting between 

 the upper sloping sides of two of the subradials, partly 

 under the first radial on the right, and connecting on the 

 left above the middle, with another piece resting upon the 

 upper truncated edge of one of the subradials, and joining 

 the first radial on the left. 



Arms ten, simple from their origin on the third radials, 

 composed of somewhat wedge-formed pieces, about as long 

 as wide on the longer side, which projects above, altern- 

 ately on opposite sides of the arms, for the reception of the 

 pinnule, so as to present a somewhat zigzag appearance. 



