456 



REMARKS ON NEW SPECIES OF CRINOIDEA, 



twenty free rays on the second division of the arms. The ray-pieces, which form the 

 base of the second division, each bear a short, blunt spine. 



The pieces composing the body are too much disarranged to exhibit their true relations 

 to each other. The basal pieces have a very prominent protuberance rising near the centre 

 of each. One of the pieces forming the ring of the basals, is much larger than the others; 

 this piece bears no prominent knob; its surface is nearly level. The raised bands, cross- 

 ing the plates, consist of from two to three parallel ridges. All these pieces arc covered 

 with granules of irregular size. 



The column is very large and strong for so small a body; it is composed of regular, 

 round disks, placed in the column; alternately one large, and then smaller ones; the mid- 

 dle one of the three being larger than the two others; the largest size pieces are quite 

 thick, compared with the thinner ones between them. The column has a uniform size for 

 about three inches below the body, when it diminishes rapidly toward the lower extremity. 

 In the smaller specimen figured, the column has nearly reached a point in four inches. 

 The extremity of the column has been lost in both of the examples. 



The smaller specimen appears to have been a free floating body, like Woodocrinus ma- 

 crodactylus, and some species of Glyptocrinus ; at least at some period during its growth. 



Size of Specimen (approximately). 



Diameter of baso, . 

 Height of base, 

 Height of first radiais, . 

 Diameter at top of first radiais, 

 Diameter of column near base, 



INCHES. 



.2(5 

 .15 

 .51 



.55 



.20 



Locality and Geological Position. — Nucleocrinus bed, near mill, Falls of the Ohio, Clark County, 

 Indiana. 



Fragments are frequently met with; good examples are very rare. 



N Cyathocrinus, with which I am acquainted, is nearly related to this species. Plates 

 and fragments of an undescribed, analogous species, is found at Buttonmould Knob, Jef- 

 ferson County, Kentucky. They belong to a larger species, and are more delicately orna- 

 mented than our species. 



The Buttonmould Knob locality is situated about one hundred feet above the top of 

 the black slate, and has been referred to the subcarboniferous division of the rocks of Ken- 

 tucky and Indiana, by those well qualified to give opinions upon this subject. 



