Nos. 620-621] THE HAWAIIAN CORAL REEFS 



431 



Numerous species of holothurians (known as sea-cu- 

 cumbers, sea-squirts, and beche-de-mer) are common in 

 the shallow waters. There are over 40 described species, 

 representing 4 families and 21 genera. A large, worm- 

 like form, Opheodesoma spectubilis, is common at Pearl 

 Harbor and Kaneohe Bay, in quiet water. It is about 

 2 ft. long and 1£ inch diameter, reddish brown mottled 

 with brown. A large, dark greenish-brown species, 

 St i< lt opus tropical is, is plentiful in the large pools of the 

 outer reef, near Honolulu. Inhabiting the tidal pools in 

 the lava rocks is another large form, Holothuria atra; 

 dark brown, and with ambulacral feet scattered all over 

 its body. Frequently associated with it is a heliotrope- 

 purple species, Holothuria citierascens. There are about 

 600 known species of holothurians, varying in size from 

 £ inch to 2 or 3 feet. They are found in all seas, but are 

 particularly abundant in the West Indies, and between 

 Asia and Australia. They feed chiefly on Foraminifera. 

 The movements of all the Hawaiian species are very slug- 

 gish ; they seem to have few enemies. All are harmless, 

 although of unpleasant aspect. They are capable of the 

 most extraordinary regeneration of parts, even of the 

 most important organ.-. Manx species show the curious 

 habit of evisceration— when alarmed they dispel from 

 the anal opening the viscera either wholly or in part. 

 In the course of a few weeks all of the lost organs are 

 replaced by a new set. 



The Crinoids or sea-lilies do not exist in the shallow 

 waters of the Hawaiian reefs. A dozen forms were col- 

 lected by the Albatross at depths of about 60O ft. These 

 all proved to be new species* although representing 8 

 wide-ranging genera in 4 families nf the non-stalked Neo- 

 Crinoidea. Crinoidal fossils have not been found in the 

 uplifted coral limestone beds of the Hawaiian Archi- 

 pelago. These forms made important contributions to 

 the Silurian and Devonian rock strata in other parts of 

 the world, during which epochs the crinoids were enor- 

 mously abundant. 



