93 
are directed to the space between them. The sphincter muscle, which pro- 
bably exists near the canal, having points of adhesion at each of its five cor- 
ners, sends off its dividing fibres across the smooth area to adhere to the stri- 
ated rim, thereby effecting the movement of the column: hence the striz at the 
outer margin do not incline to the centre. 
The Auxitiary Sipe Arms (fig. 3. and 8.) are formed of numerous round 
joints, proceeding at irregular intervals from the spaces between the angles of 
the larger joints. 
The Cup-uike Portion (fig. 1.) on the summit of the column is formed by 
plates resembling those of Cyathocrinites Planus, except that the lower sur- 
face of the pelvis, where it articulates to the column, is somewhat pentagonal. 
The Five Arms are formed of one-arm joint and a cuneiform one, sup- 
porting two hands, each composed of two joints, and a cuneiform one sending 
off'a finger, and probably also another series of the hand joints. 
