Belemnocrinus, and description of two new species. 255 



portion of the calyx is somewhat distorted by pressure, it was 

 at first supposed to be a Belernnocrinvs. Upon removing the 

 calyx from'the surrounding matrix and arranging the plates in 

 their natural position, it was found to possess a series of large 

 Bub»radials resting upon the basals, the anal plates arranged as in 

 faeriocrinus, thus exhibiting a fundamental difference from 

 rinus. Careful examination of the interior part of the 

 cylinder formed by the basal plates, showed that they are thin 

 and enclosed a comparatively large cavity, reaching nearly to 

 the bottom of the cup, thus proving in 'a highly satisfactory 

 manner the value of the peculiar characters of Belemnocrinns. 



We are unable to agree with Dr. White in referring this 

 genus to the Cyathocrimdce, as it does not possess the general 

 appearance of that group, nor does it agree in the generic for- 

 mula as herein given. The slender ovoid or cylindrical base, 

 the long yolid basal plates, the shallow cavity in their upper 

 part, and the comparatively small size of the visceral cavity -lire 

 features which remove Bekmnocn 'mi* -far from Ct/uthocronts, or 

 any of its allied genera. These characters show its affinities 

 rather with the Jurassic genus Apiocrinus, to which in the con- 

 struction of the calyx and inner cavity, it is more similar and 

 seems to bear a closer relation, than to any other known group. 



The resemblance to the recent genus R/tizorrin!>*\ pointed out 

 by Count Pourtales, is very close and interesting, even more so 

 than he perceived, since we cannot agree with him thai the first 

 radials are movable in Belemnocrinvs. On the contrary we find 

 them to be closely joined with each other and with the anal 

 plate by exact sutures, the anal plate being in line with them, 

 forming the cup, and supporting upon its upper face the heavy 

 proboscis. The succeeding radials have spaces between the 

 rays, showing them to have been free. The most important 

 difference, and indeed the only essential distinction between 

 these genera in their external structure is found m the solid 

 1"'' 'h eeis and covered dome of Belemnocrinus. 



As a result of the foregoing observations we give now the 

 following revised 



Generic Formula. 

 , Basal plates, five; long, narrow, forming an ovoid to cylin- 

 drical cup, which is nearly solid, having a small central perfo- 

 ration, and a shallow subcorneal excavation at its upper end, 

 which forms a part of the visceral cavity. 



Radial plates, four to five X 5 ; the first series with the anal 

 Plate joined at the sutures and composing a part of the cup; 

 the succeeding radials free. . , 



1 Anal plate, one ; supporting a rather long, comparatively 

 large proboscia Dome covered by solid plates, arrangement 



