AND BLASTOIDS. 191 



species are very different, the basal cup in our species occupy- 

 ing one-third the height of the calyx, besides being deeply ex- 

 cavated for the reception of the column. />. moral us is a very 

 characteristic fossil of the locality, and is found in excellent 

 preservation. The color of the specimens is very dark. 



Height of specimens, without the stem, ranging from an inch 

 and a quarter to two inches and a half in the larger ones. 

 Calyx subglobose, truncated at the arm regions: the sides curv- 

 ing very uniformly from the column to the arm bases. Larger 

 specimens comparatively more elongate than smaller on 

 Surface of plates devoid of ornamentation or any kind of mark- 

 ings, except the first radials have a small angularity following 

 the middle portion of each plate in a vertical direction, which 

 extends frequently into the basals. Sutures, although quite 

 distinct between the radials, not marked by indented lin> 



The basals occupy fully one-third of the height of the calyx; 

 they form a rounded cup or basin, which, seen from above, has 

 a strictly hexagonal outline. Interbasal suture passing from 

 the posterior to the anterior side; frequently obscure. 



First radials one-quarter to one-half higher than wide. Sides 

 slightly contracted at both ends, somewhat bulging at their 

 middle portions, and abruptly inflected toward the vault, which, 

 including the first interradials. lies in a plane at right angles 

 to tlie sides of the calyx. Facets for the attachment of the 

 higher radials above one-third the width of the plates. Second 

 radials small: twice as wide as high or even wider: upper and 

 lower sides convex: rounded like arm plates. Third radials a 

 little larger: triangular, bifurcating: upper angle very sharply 

 pointed, and the upper part bent inward so as to separate the 

 two divisions: the sloping sides of the plates concave. The third 

 radials support from each side a short quadrangular pi 

 which, together with the preceding plates, form a part of the 

 calyx, being connected with their fellows by the intercalation 

 of interradial plates. They are succeeded by a cuneate free 

 plate, and again by two rows of interlocking arm pieces. First 

 anal plate about the size of the first radials, but more strongly 

 inflected towards the vault. 



Arms biserial, two to each ray: about twice as long as the 

 height of the calyx or a little more; comparatively stout: grad- 

 ually tapering to their tips. The arm plates have parallel 



