424 PALEONTOLOGY OF ILLINOIS. 



Arms somewhat rounded on the dorsal side, each bifur- 

 cating on the sixth or seventh piece above the second pri- 

 mary radials, and composed of wedge-formed pieces that 

 are a little longer than wide on the longer side. Above the 

 bifurcations these pieces are somewhat constricted, and 

 each one projecting laterally above on its longer side, for 

 the reception of the pinnulse, so as to present a rather zigzag 

 appearance. Pinnulse moderately stout, and rather dis- 

 tantly separated from each other ; composed of joints a 

 little more than tAvice as long as wide. 



Surface of body plates even, and finely granular. 



Hight of body, 0.10 inch to top of first radial pieces, 

 where it measures about 0.20 inch in breadth; arms, about 

 0.75 inch in length. 



In size and general appearance this species is quite similar to 8. dicho- 

 tomus, of Hall, with which it also agrees in having its arms bifurcating 

 but once above their origin on the second radials. It differs, however, 

 in having its second radial pieces rounded instead of angular, and dis- 

 tinctly longer in proportion to breadth, as is also the case with all the 

 arm joints. It also differs in having two arms to each ray, all around, 

 instead of only one in the anterior ray, as well as in the number of 

 pieces in each arm below the bifurcations. Its arms are likewise pro- 

 portionally more slender. 



Locality and position Lower division of the Burlington group, at 

 Burlington, Iowa. Lower Carboniferous. Mr. WACHSMUTH'S collec- 

 lection. 



SCAPHIOCRLNTJS FISCELLUS, M. and W. 



PI. 1, Fig. 3. 

 Scaphiocrimis fisceUus, MEEK and WORTHEX. Proceed. Aead. Nat. Sci., Phila., 1869, p. 146. 



BODY very small, somewhat cup-shaped, about once and 

 a half as wide as high, rather broad and subtruncated be- 

 low, with moderately expanded sides. Base very small, 

 flat, and hidden by the column, when the latter is attached. 

 Subradial pieces convex, curving unde'r to connect with the 

 base, and extending about half way up the sides; three of 



