NO. 7 SEA-LILIES AND FEATHER-STARS CLARK 39 



grooves into closed tubes and prevents the appropriation of food 

 particles by the ectoparasitic crustaceans, the ophiurans, and the 

 polynoid worms. 



The larger commensals living on the crinoids are usually striped or 

 banded, and resemble them more or less closely in color, though in 

 many cases the closely related noncommensal species are quite plain. 

 This may or may not be the case with the myzostomes. 



In regard to the parasites and commensals of the comatulids there 

 is one curious feature which stands out very prominently — the 

 majority of the records, especially of the larger and more vigorous 

 types, are based upon species of the family Comasteridae, probably the 

 most specialized of all the comatulid types. 



COMMENSALISM OF THE CRINOIDS 

 A number of small comatulids and the young of certain others may 

 be considered as truly commensal, living as they do in the cavities of 

 large sponges and gathering the minute organisms brought to them 

 by the currents flowing into the afferent openings of the host. Many 

 others habitually cling to gorgonians or withdraw into crevices in 

 corals where they live symbiotically, but quite independently of the 

 supporting organism. 



ECONOMIC VALUE OF THE LIVING CRINOIDS 



Economically the crinoids serve no useful purpose — at least up to 

 now they have been put to none. They cannot be eaten, and they are 

 not, so far as we know, eaten by any fish or other animal that serves 

 as human food. 



As a result of their ordinarily fixed mode of life it is possible that 

 they might be used to furnish an index of the density of the finer 

 plankton content of the water in which they live, though it is probable 

 that other more generally distributed animals with more or less 

 similar feeding habits would serve the purpose better. 



Because of their beauty and delicacy of form as well as on account 

 of their rarity they are frequently preserved and offered for sale as 

 curios in Japan and China and, less frequently, in India, Oceania, 

 Australia and the West Indies. 



In southern Japan crinoids are frequently brought up on the long 

 lines used for fishing in deep water in Sagami Bay. The comatulids, 

 because of their beauty and delicacy of form, are called " komachi " — 

 a name originally borne by an exceptionally well-favored lady of the 

 court upwards of a thousand years ago — while the local stalked 

 crinoid {Metacrinus rotundus) is known as the " bird's foot." The 



