BRANCH ECHINODERMA TA : S TARFISHES, ETC. 125 



preparing the trepang is almost entirely in the hands of 

 the Malays, and every year large fleets set sail from 



FIG. 23. A sea-cucumber, Pentacta frondosa. (After Emerton.) 



Macassar and the Philippines to the south seas to catch 

 sea-cucumbers. 



Feather-stars (Crinoidea) . The feather-stars or sea- 

 lilies or crinoids (fig. 24), as they are variously called, differ 

 from the other Echinoderms in having the mouth on the 

 upper side of the central disc, and in the fact that all of 

 the species are fixed, either permanently or for a part of 

 their life, being attached to rocks on the sea-bottom by 

 a longer or shorter stalk which is composed of a series of 

 rings or segments. The central disc is small and the 



