38 



they are in Z. maniformis, and we are led to infer, from the 

 figure, that it had ten arms while our species has only nine. 



Found in the Kaskaskia Group, in Randolph County, Illinois, 

 and now in the collection of Wm. F. E. Gurley. 



SCAPHIOCUINUS MAKTINENSIS, U. sp. 



Plate IV, Fig. 9, Calyx, part oi the column, and part of the arms. 



Calyx cup-shaped, more than one and a half times as wide as 

 high, very evenly expanding from the column to the top ; sut- 

 ures distinct; surface smooth or finely granular. Column small, 

 round and composed of alternately thicker and thinner pieces. 



Basals form a little cup, with sharp, high angles, at the top. 

 Subradials twice as large as the basals. First radials larger 

 than the subradials, widei' than high, truncated nearly the en- 

 tire width for the second radials, from which they are separated 

 by a gaping suture. The upper part below the gaping suture 

 is quite prominent and convex in the middle part, and the 

 superior lateral angles are slightly truncated, leaving the suture 

 at the top depressed. The second radial or first brachial, in 

 the only arm preserved, in our specimen, has a length greater 

 than the diameter at the upper end, and the second brachial is 

 longer than its greatest diameter, axillary, and supports an arm 

 upon each upper sloping side. The two brachials together, are 

 round externally and contracted on the sides. 



The arms are short and coarse, one of them divides on the 

 seventh plate and the other remains single throughout its 

 length. The arms are composed of remarkably long, cuneiform, 

 alternately projecting plates, that bear alternately, short, 

 strong, long-jointed pinnules. Only pieces of the other arms 

 are preserved, in our specimen, but one of them is shown to 

 have had only a single brachial, which is long, contracted in 

 the middle, at the sides, and axillary. The arms are not, there- 

 fore, uniform in structure. The azygous side is not visible. 



This species is so different from any hitherto described, that 

 no comparison with any of them is necessary, in order to dis- 

 tinguish it. 



Found in the Kaskaskia Group, in Martin County, Indiana, 

 and now in the collection of Wm. F. E. Gurley. 



