110 
PALAEONTOLOGY QF NEW-YORK. 
Mariacrinus phunosus (n. s.). 
Plate III. Fig. 6 - 11. 
Body small, obconic or turbinate : surface ornamented by strong radiating 
ridges proceeding from the centre of the plates. Basal plates about as 
long as wide. First radial plates a little longer than wide : second and 
third radials scarcely longer than wide. Interradial plates one below, 
succeeded by three ranges of two each. Radial and interradial plates 
strongly marked by radiating ridges. Brachial plates two at the base, 
which give origin to two ranges in direct line of three plates each 
and an intercalated plate, which rests upon the contiguous sloping 
edges of the two outer lower brachial plates; and above this, two 
ranges of two small plates each, precisely as in the interradial plates. 
From the summit of these originate four arms, composed of subcuneiform 
plates with lateral tentacles originating from the thicker sides. Ten- 
tacula near the base of each outer arm of the four, originating on every 
second plate, and sometimes an interval of two plates without tenta¬ 
cles ; while on the two inner arms there appear to be no tentacles till 
about the eighth joint. Tentacula round, gradually tapering : joints 
short. 
Column round, comparatively large; consisting, near the base of the 
body, of nearly equal joints. 
Tins species, in tlie aspect and structure of the body, ornamenting of surface, etc. 
scarcely differs, except in size, from M. pachydactylus. The arrangement of the 
brachial joints, and the character of the arms, are most conspicuously distinct. 
The first bifurcation of the brachial plates is,however, the same; but at the second 
bifurcation, the lateral brachial plates sustain the outer arms, which correspond to 
the auxiliary arms in the preceding species; while the upper ones of the central 
range, together with the inner oblique edges of the outer ones, sustain two small 
plates which give origin to the central pair of arms, corresponding to the main 
arm of the preceding species, but which is here reduced to the condition and 
structure of two of the armlets, and furnished in like manner with tentacula. The 
character of the species is thus most remarkably changed, by a modification of the 
brachial arrangements, reducing the whole number of these appendages to four from 
each ray, or twenty altogether; while in M. nobilissimus there are more than sixty 
from each ray, and more than three hundred altogether. 
