THE ANIMxVL LIFE OF THE GRULl'. 487 



They are said to feed on seaweed and also on dead fish and decaying mattei- of 

 various kinds. The large purple-black species/^ with long, slender, awl-shaped 

 spines, prefers the deeper water in the holes toward tlie outer edge of the reef. 

 With it occurs a similar species " in whieli tlie long spines are banded gray and 

 black. Both species are known as Wana, or sea eggs, and are much sought 

 for by the Ilawaiians, Avho are very fond of them. 



The spines of the wana are both sharp and brittle and inflict a serious 

 wound. If the native fisherman is so unfortunate as to be injured by one he 

 will bite the wound savagely in order to grind the spine into fine fragments 

 so that the pieces will come out later on with the pus. 



The 1)eautiful club-spined ~ urchins are quite conniion at eei-tain ]ilaces 

 on the reef, and are often on exhibition in the Acpiariiuu in Honolulu. They 

 are as large as the preceding species, but are a reddish-brown color, and the 

 spines are heavy and blunt and imperfectly triangular. 



A curious rough rock urchin.'' the haukeuke, has tlie spines short and 

 blunt over the back, but long and dull-pointed about the edge. They are 

 fond of the rough sea and adhere to the blaek lava rocks exposed to the full 

 dash of the waves. 



A large lieart-shaped urchin,'' covered with fine short brown hair-like 

 spines, is known as the sea biscuit or heart-urehin. Other forms are occasion- 

 ally collected in shallow water, l)ut the ma.i(»rity of the Echinoidea are found 

 in deeper water offshore. The number of species inhabiting the Hawaiian 

 waters is not determined, but it is known to be a rich fauna, there beiim- a 

 number of rare species. 



Starfishes. 



While the true starfishes^" are fairly common in the deeper water otV- 

 shore, they are not very abundant on the coral reef. As a matter of fact. 

 it is a great find to collect a specimen of any size from the reefs about Oaliu. 

 It is necessary to understand at this point that in the tyi>ical stai-fish the anus 

 are usually, though not always, five in number and that, as a I'ule. they are not 

 sharply marked off from the centi'al disk, as is the case with the bi-ittle-star- 

 fish.ii two or three species of which are plentiful in shallow water. In 

 the true stars the feet are located in a definite groove, while in the brittle stars 

 the grooves are not present. 



The connection of the feet with the water-vascular system is very inter- 

 esting. On the back between two of the arms nuiy be seen a curiously rougli- 

 ened plate i- that in reality is a sieve through Avhich the water is strained l)efore 

 it enters the system. Connected with this sieve-like body is tlie stone-canal. 

 It runs downward and connects with the ringed-canal which encircles the 

 mouth; from this canal five radial canals, on.e for each arm, ])ass outward 

 just above the ambulacral grooves. The radial-canals give olV side bi-anches 



^ Diademn pniii'i.spii(inn. " Ecliinotlirix desori. ~ Ufti'rori'utrotes sp. » Podophorn jtediii-ra. 



" Brixsiis carinatus. ^'> Asterioidea. ^^ Ophitiroidea. i-' Madreporite. 



