16 



line. The sutures are so obscure between the small plates, in 

 some of the areas, that it cannot be determined whether or not all 

 the areas are exactly alike. The arms are separated about equally 

 distant from each other, whether by the interradials or inter- 

 secondary radials. 



There seems to be no azygous area in the calyx. 



The vault, in our specimen, as may be seen in the illustration, 

 is broken away at the summit. It is, however, highly convex, the 

 convexity probably equalling the height of the calyx, and covered 

 with ornamented polygonal plates arranged in peculiar and system- 

 atic order. The sutures are distinct, even between the smaller 

 plates, and the edges of the plates are beveled, and between the 

 larger plates the sutures are widely grooved. The plates are de- 

 pressed convex, concave in the center and more or less sculptured 

 and granulous. The smaller plates are over the arm furrows and 

 regularly interlock. The plates toward the central area are large 

 and polygonal. The plates in the interradial areas are elongated 

 and arranged fan like, in some of the areas, and more like a key- 

 stone arch in others, which have a very long, wedge shaped plate 

 in the middle. There are eight or ten plates in each depressed 

 interradial area. A horizontal furrow crosses the top of each of 

 the last plates of the calyx and penetrates the vault at the suture 

 between the plates of the interradial areas. There are, therefore, 

 eight or ten horizontal elongated pores or passages that penetrate 

 the vault between each of the arms. They are shown in the 

 illustration. This subject will be further considered in remarks 

 at the close of the descriptions of Dolatocrinus in this article. 



Found in the Hamilton Group, at Louisville, Ky., and now in 

 the collection of Wm. F. E. Gurley. 



DOLATOCRINUS ORNATUS VCIV. ASPERATUS, n. VCir. 



Plate II, Fig. 4, basal view, Fig. 5, view of the vault; Fig. 6, 



side view. 



Calyx low, basin shaped, flattened or truncated at the base as 

 far as the extent of the second radials; columnar cavity small; 

 primary radial ridges prominent; surface of all the plates closely 

 and radiately sculptured and pitted. 



Basal plates hidden by the column, which is round and pierced 

 with a cinque-foil canal. First primary radials longer than wide 



