18 



DOLATOCKINUS ORNATUS, Meek. 



Plate II, Fig. 7, basal view; Fiy. 8, summit view; Fig. 9, side 

 view of the same specimen from Columbus, Ojjio. 



The following is the definition of this species, by Meek, from 

 the Proceedings of the Academy of Nntural Sciences of Philadel- 

 phia, 1871, p. 57. It has never, before, been illustrated. 



"Body including the vault, depressed subglobose, the portion 

 below the arm bases being a little higher than the vault, with 

 nearly vertical sides above, but rounding under below to the some- 

 what flattened under side; arm bases protuberant, mainly in con- 

 sequence of the rather deep furrows or sinuses of the vault over 

 the interradial areas; vault composed of irregular pieces, each of 

 which projects in the form of a little sharply prominent node or 

 short spine, the largest of which are situated around the nearly 

 central ventral tube, and on the elevations between it and the arm 

 bases. Base small, a little compressed within the shallow concav- 

 ity of the under side, and marked by a distinctly indented column- 

 facet, which occupies near three-fourths of its entire breadth, so 

 that only a narrow ring, as it were, of the basal pieces can be 

 seen when the column is attached. First radial pieces compara- 

 tively large, extending out nearly horizontally, or only a little 

 arching upward, and with their inner ends curving slightly into 

 the shallow central concavity; all wider than long, and hexagonal, 

 with the upper (outer) side of each longer than any of the others. 

 Second radial pieces about half as large as the first, wider than 

 long, and quadrangular in outline. ( In one ray of the typical 

 specimen the second radial is abnormally wanting, while the third 

 is larger than usual.) Third radials about as large as the second> 

 from the curved-up edges of which they rise vertically wider than 

 long, and pentagonal in form; bearing on each of their superior 

 sloping sides a smaller secondary radial, each of which supports 

 another smaller, more or less cuneiform piece, from which the 

 arms arise; thiis making two arms from each raj', unless the num- 

 ber is increased by bifurcations after tliey become free; arms 

 unknown, but ajjparently composed, at their origin, of a double 

 series of alternating pieces. 



"First interradial pieces, somewhat larger than the first radials, 

 about as wide above the middle as their length, eight or nine 

 sided, with the lower part of each curving under to connect with 



