216 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



Throughout its range the rosy feather star is preeminently an inhabitant of rugged 

 and rocky shores and of rough, hard and rocky bottoms, where it lives attached to 

 seaweed, polyzoans, hydroids, sponges, etc., or even to the rocks themselves. At 

 Cork it has been found clinging in numbers to stones below the low tide mark (Paddy 

 from Cork, 1895). 



In deep water, in from 37 to 90 meters and beyond, where the wave action is 

 less strong than along the shores, it is more generally distributed, though usualty 

 less abundant than in favorable localities in shallow water. While rocky regions 

 still remain the favorite habitat, a considerable variety of bottom is frequented. Here 

 it has been recorded from gravel (Forbes, 1851, Herdman, 1895), sand and gravel, 

 sand and stones, stones and shells, broken barnacles and serpulae, fine mud (Forbes, 

 1851), and clinging to nullipores (Herdman, 1895). It has once been reported from 

 mud in 5 to 11 meters (Forbes, 1851). 



Habits, etc. During a visit to Roscoff, Dr. F. A. Bather made a series of careful 

 observations on the habits and reactions of this species. 



He says that, while swimming has been observed in both endocyclic and exocyclic 

 comatulids kept in an aquarium, these animals as a rule remain attached by their cirri 

 to rocks, to the bottom ooze, to seaweeds, or to other marine animals. In this posi- 

 tion the arms are outspread, and the small branches or pinnules that line their sides are 

 kept slightly waving. If the water be ruffled, the first impulse of the crinoid is to flat- 

 ten its arms out suddenly and to hold on to the rock or other object with its pinnules. 

 The pinnules of an Antedon can be bent in any direction, those near the extremity of 

 the arm being especially active. If its extremity be touched by any irritating sub- 

 stance, the arm is erected at right angles to the upper surface of the animal and so 

 removed from the other arms, while the pinnules move somewhat like the legs of a fly 

 that is cleaning itself. If, however, this proves ineffectual, the arm bends over towards 

 another on the opposite side, the pinnules of which then assist in the operation. The 

 pinnules move in this manner to rid the arm of sizeable fragments of foreign matter; 

 but the hooks at the end of the pinnules can catch and retain minute fragments which, 

 as they decay, attract animalculae and so furnish food for the animal. If a stimulus 

 be applied to any point on the under surface of the animal, the arms on the side from 

 which it comes are simultaneously and forcibly pressed down, apparently to create a 

 current that will wash away the irritant. An arm, if it be cut off, will continue to 

 move for a short time. The crinoid, however, flattens its remaining arms, and remains 

 immovable for half a minute, then slowly crawls in a direction away from the wound. 



Antedon does not appear to like the light, and if placed on the surface of a stone 

 in a glass vessel, always prefers to crawl to the under side, where it remains fixed by 

 its cirri. If, however, a strong light be reflected on to the under side of the stone while 

 the top is kept dark, the animal will crawl back to the top. It is by crawling that the 

 crinoid usually moves from place to place. The amis on the side towards which it 

 intends to move are stretched out; the pinnules are curved back towards the body, 

 like so many grappling hooks; and the arms are then curved up in S-fashion, thus 

 dragging the animal along. Meanwhile the arms of the opposite side move in the con- 

 verse way, and their pinnules are directed away from the body so that they push in- 

 stead of pull. Nicols (1960) made a fine study of the histology of the tube feet and 

 their role in feeding behavior. 



