FOSSILS OF THE KEOKUK GEOUP. 493 



except below, where they curve abruptly inward to connect 

 with the base ; all seen, presenting pentagonal general out- 

 lines on their outer faces. Eirst radial pieces nearly twice 

 as wide as high, pentagonal in form, and truncated their 

 entire breadth above for the reception of the second 

 radiaLs. Anal pieces unknown. Second radials longer 

 than wide, strongly constricted in the middle, with steeply 

 sloping sides for the support of the arms above. Arms 

 simple from their origin on the second radials, slender, and 

 composed of long, rounded, somewhat constricted joints, 

 which are obliquely truncated at the ends, with the upper 

 end of all projecting alternately on opposite sides, for the 

 support of long, very slender tentacles, composed of long 

 joints. 



Breadth of body, near 0.30 inch ; hight, 0.15 inch ; arms, 

 apparently about 1.12 inches in length, and only 0.05 inch 

 in thickness at the constricted part of the lower joints ; 

 first four joints, 0,32 inch in length. 



In its depressed body, with, nearly vertical sides and broadly trun- 

 cated, concave lower part, this species seems to resemble S. unicw, Hall, 

 as near as can be determined from a description alone. It differs, how- 

 ever, in having the arms simple from their origin on the second radials, 

 with long, instead of very short joints. It is peculiar in the broadly 

 truncated and concave character of its under side, as well as in the 

 sleuderness of its arms and pinnulae. The latter are also remarkably 

 distant from each other, owing to the length of the arm joints. 



Locality and position Keokuk division of the Lower Carboniferous 

 series ; Crawfordsville, Indiana. 



SCAPHIOCRINUS uxicus, Hall. 



PL 15, Fig. 5. 

 jScaphiocrinus uniau, HALL, 1861. Prelim. Deecr. Xe\r Crinoidea, p. 8. 



Locality and position Keokuk group ; Crawfordsville, Indiana. 



