ECHINODERMS 71 



Brittlestars. — Brittlestars are found everywhere, usually under 

 stones, in the interior of coral heads or sponges, about the roots 

 of seaweeds, clinging to gorgonians or other plantlike animals, 

 or buried in mud. Some live only among the spines of sea urchins, 

 especially on the under side, or on crinoids or sea lilies. Many 

 may be found by breaking up coral heads or cutting up large 

 sponges. They should be dropped at once into 70 percent alcohol. 

 The larger, tougher kinds may be dried after a few days in 

 alcohol. The arms of the larger ones may usually be manipulated 

 under alcohol so that they all point in one direction, which saves 

 space in packing them for shipment. 



Crinoids or featherstars. — Featherstars are often common on 

 reefs, particularly below low-water mark on the windward side, 

 or clinging to fringing gorgonians or other growths. They are 

 usually found under large stones or in shaded situations. They 

 should be placed at once in strong alcohol (75 percent solution). 

 They almost always become more or less broken, but this does 

 not prevent their being studied. 



Some crinoids, known as sea lilies, grow up from the bottom 

 on long stalks. These are especially desirable, as very little is 

 known about the species occurring in relatively shallow water. 

 It is possible that some of these may be obtained from divers. 



Holothurians or sea cucumbers. — Sea cucumbers are found on 

 rocks between tide marks on reefs, under fragments of rock, 

 among seaweeds, or buried in mud. They vary in length from 

 less than an inch to about 4 feet. Small ones may be dropped into 

 70 percent alcohol. It is scarcely practicable to attempt to pre- 

 serve any over a few inches in length without abundant facilities, 

 as they must be narcotized and then injected and carefully 

 hardened because of the great amount of water in their tissues. 



