THE ANIMAL LIFE OF THE GROUP. 479 



dance, while such genera as Pavouia, Favia, Leptastrca and fi/pjuisln <t occur 

 in isolated places here and there in certain favorable localil ics. 



The mushroom coral,--' or huahua akai, forms a rejiiarkable group of 

 solitary corals that are fairly common, esi)ecially in hok'S or reef pools on the 

 outer edge of the reef. They take their name from their i-csciiiljlanco to the 

 inverted head of an expanded mushroom. They are remarkable and beaulifiil 

 objects, and make handsome souvenirs of a day's visit to a coral reef. The 

 "sea mushroom." or in fact any of the corals, can be easily cleaned if they 

 are placed in a bucket of fresh water before they have been out of Ibe sea- 

 water long enough for the animal to die and begin to dry up. Ivu'li day or so 

 the water should be changed and the macerating animal washed out by a 

 stream of water from the hydrant. When thoroughly cleansed the coi-;il 

 should be placed on a clean board in the sun to bleach. 



Perhaps the most strikingly beautiful of the stalked corals is a species ^*^ 

 which so far has only been found on Oahu. growing on the edge of the small 

 coral islands in Kaneohe Bay. When alive the animal is a rich red-orange 

 color and has the top of each short branch surrounded by a single orange- 

 yellow polyp that when expanded is three-fourths of an inch in diameter. On 

 the approach of danger the animal can completely withdraw within the cup 

 in which it lives. 



So far as known, the bi-ain corals •■^ have never been taken in Hawaiian 

 waters. They, together with many other forms offered for sale in the curi- 

 osity shops of Honolulu, doubtless come from the islands of the south Pacific 

 or from the Philippines. 



The Eight-Payed Corals. 



While the Alcyonarians are seldom seen by the reef coliectoi-. it is a 

 matter of interest to know that of the sixty-eight species of the "eight-rayed 

 corals" taken by the Albatross on its epoch-making cruise about the islands, 

 thirty-nine were described as new to science in Dr. 0. ('. XuHinu's i-eporls on ihe 

 material. He states that of the three orders of Alci/otiaria discussed in his paper, 

 the first.^- including the colonial forms, usually typiti(Ml by the oruan-pipe coral, 

 are represented by only five species. 



Sea-Pens and Ska-Fans. 



The order"'-' including the sea-pens and similar forms whei-e tlu' coli«nies 

 are arranged bilaterally and symmetrically on an axial stem. ha\-e si.\t<en 

 species in the off-shore fauna. The sea-fans. sea-i)luines and their allies loi-m 

 the most abundant order.^-^ Like the othei- orders of the class, they nil have 

 eight-rayed polyps. The beautiful h.oi-ny li-ee oi- bush-like growth 1o be seen 

 in museums, however, gives but lillle idea of the ;iii|ieai-ance of the living 

 animal. Forty-eight species ai-e included m the list of Hawaiian s|)ecies. but 



^0 Funmidfv. ^^ DmidroiihiUin iiKnini. »' J/cfuif/ciHO. "- Alcyonarta: 3n p,.in,nliil<ii-i-a. 



^* Gorffonacea. 



