FROM THE PALAEOZOIC ROCKS OF INDIANA, KENTUCKY AND OHIO. 



457 



CyATIIOCPJNUS 1NSPERATUS, n. S. 

 PL XXV J I, Fig. k. 



The body below the free rays is nearly as wide as high — obconical in form; above the 

 free rays the proboscis is greatly expanded, being nearly as wide, and longer than the 

 body below. The proboscis, or rather, sack, is composed of several rows of large pieces, 

 one above another; hexagonal; longer than high. The ends of the pieces are equally 

 truncated on both sides, forming a sharp angular point, by which the rows are joined; the 

 pieces in adjacent rows alternating one above the other of those in the adjoining rows. 



The plates of the calyx are very thin ; basal pieces long ; the first radials, subradials, and 

 the two first anal pieces arc nearly equal in size. The arms are long ; very small ; bifur- 

 cate on the summit of the second small first radial ; giving oft' additional branches on the 

 third piece above the branch below, three or four times. These branches also bifurcate. 

 The precise arrangement of these branches is not clearly made out, owing to the condition 

 of our specimen. The free rays do not appear to have been provided with pinula ; they 

 are round, composed of a single row of short pieces, nearly of equal size. 



Size of Specimen. 



Diameter of body at base of free rays, 

 Height to free rays, .... 

 Height of sack above second anal piece, 

 Diameter of sack, ..... 

 Length of free rays, .... 



INCHES. 



.25 



.27 



.50 



.35 to .40 



.45 to .50 



Locality and Geological Position.— Crawf'ordsvillo, Montgomery County, Indiana. It occurs not 

 abundantly in the silicious sandstones of the knob formation — Safford's silicious group — at the base of 

 the siibcarboniferous limestone. In some bods of these measures the fine mud has swept into the 

 locality of the crinoidea, apparently burying them alive. These bodies are attached to the columns; 

 all extended one way; the fingers unbroken, and the most delicate parts preserved in the now con- 

 solidated mud. The bodies have decayed, and left perfect moulds of the animals in the soft rock, to 

 mark the place of their burial. In some of the beds water has carried lime, in solution, into these 

 cavities • these arc now filled with crystallized limo. Eemarkable specimens of the empty moulds of 

 crinoids are abundant. 



Remarks. — Our specimens are attached to a block of stone, and somewhat distorted by 

 crushing. The measurements are only approximately correct. 



This species will be readily separated from G. rotundas, Hall, which it most nearly 

 resembles, by the length and expansion of the proboscis, the greater length of the basal 

 pieces, and the marked difference in the character of the pieces composing the arms. In 



VOL. XIII.- 



-58 



