FOSSILS OF THE BURLIXGTOX GROUP. 419 



having the articulating surfaces each marked Avith two very 

 distinct transverse furrows. First anal piece a little longer 

 than wide, hexagonal in form, and resting upon the trun- 

 cated upper end of the odd subradial between two of the 

 first radials. beyond which it projects nearly half its length; 

 truncated above for the reception of a second anal. Other 

 parts unknown. 



Sutures distinctly channeled, so as to impart a moderate 

 convexity to the plates. 



Hight to top of first radials, 0.20 inch; breadth, 0.46 inch. 



This is a typical ScapJtiocrinm, as far as its parts are known, and 

 seems to be most nearly related to 8. simplex, of Hall, from which it 

 may be at once distinguished, however, by its channeled sutures, con- 

 vex plates and peculiar .sculpturing. 



Locality and position Lower Burlington beds, of the Lower Car- 

 boniferous, at Burlington, Iowa. No. L'74 of Mr. WACHSMUTH'S collec- 

 tion. 



SCAPHIOCRLNTS TETHTS, M. and "W. 



PL 2. Fig. 13. 

 Scaphiocrinus Tethys, MEEK and WOBTHKS. Proceed. Acad. Xat ScL, Phila., 1869, p. 143. 



BODY under medium size, expanding rather rapidly from 

 the column to the top of the first radials, where it is about 

 one-fourth wider than high. Base small, twice to three 

 times as wide as high. Basal pieces very small, wider than 

 high, and pentagonal in form. Subradial pieces slightly 

 wider than long, pentagonal, excepting two on the anal 

 side, which are hexagonal, there being no well defined angle 

 at the middle of the base of any of them. Eirst radials 

 larger than the subradials, a little wider than long, and all 

 pentagonal. Second radial pieces rather more than twice 

 as wide as long, rounded and a little constricted in the 

 middle, and somewhat expanded at the ends ; all pentag- 

 onal in outline, and each supporting two arms on its supe- 

 rior sloping sides. 



