204 
PALEONTOLOGY OF NEW-YORK. 
594. 1. MACROSTYLOCRINUS ORNATUS (n. sp.). 
Pl. XLVI. Fig. 4 a-g. 
Body small, composed of three pelvic plates of moderate size, succeeded by five large costal 
plates, three of which are heptagonal and two are hexagonal, having all truncated upper margins 
on which rest the scapular plates, and to which succeeds in each series a single arm-plate; a 
single hexagonal or heptagonal interscapular plate is interposed between the scapular plates, 
its lower oblique edges resting on the short oblique upper edges of the costal plates ; the inter¬ 
scapular plate supports two small plates above it, which are succeeded by other small plates ; 
each arm-plate supports upon its oblique upper edges a pair of arms, which diverge from each 
other; each arm in its lower part is formed of a single series of eight or nine plates, above 
which it is composed of a double series slightly interlocking with each other ; surface of plates 
of the body tuberculo-striate, the lower ones being marked with interrupted ridges or striae 
with few tubercles, while the upper ones, or the scapular, interscapular and arm-plates, are 
covered with minute tubercles, sometimes elongated in a direction from the centre to the upper 
and lateral margins ; two or three of the lower simple joints of the arms are tuberculate or 
crenulate on the upper margins, while the upper or double series of plates of the arms are 
marked by distinct round or subangular tubercles along the centre. 
The body of this species is very prettily ornamented by elevated striae and tubercles, some¬ 
what similar to the body of T/iysanocrinus liliiformis , but more strongly, particularly in its 
upper portion. The arms are very long and much diverging, destitute of fimbriae. The distin¬ 
guishing feature of the arms is the simple series of plates in the lower part, with a double 
series above ; which portion, in fragments, may be distinguished by the prominent node or 
tubercle upon the back of each joint, with less prominent ones upon the sides. The column of 
this species is entirely unknown, but it is probably round, with alternating thicker and thinner 
joints, the margins in some parts probably nodulose. 
Fig. 4 a. The specimen described, showing the body and four of the arms, all broken off before 
reaching their termination. 
Fig. 4 b. The structure as ascertained from the specimen 4 a. 
Fig. 4 c, d. Two costal plates enlarged, showing their striate and tuberculo-striate character. 
Fig. 4 e. A pelvic plate enlarged, showing a striate surface only. 
Fig. 4 /. A plate from near the base of the arms, showing the tuberculo-crenate upper edge. 
Fig. 4 g. Several joints from the upper part of the arms enlarged, showing the strong tubercle 
on the back of each plate, with smaller ones on each side. 
Position and locality. In the shale at Lockport. 
(Collection of Col. Jewett.) 
