THE AXmAL LIFE OF THE GROUP. 479 



dance, while such genera us I'aviinin, Furia. L< pfnatrca and ('milidstrKi occur 

 in isolated places here and there in certain favorable localities. 



The mushroom coral.-'' or huahua akai, forms a remarkable ,i>roup of 

 solitary corals that are fairly connnon, especially in holes or reef pools on the 

 outer edge of the reef. They take their name from their I'csemblance to the 

 inverted head of an expanded mushroom. They are remarkal>le and beautiful 

 objects, and make handsome souvenirs of a day's visit to a vovn\ 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 liefore they have been out of the sea- 

 water long enough for the animal to die and begin to dry up. Each 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 coral 

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



Perhap.s 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 brain 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 Eigiit-R.wed Cor-\ls. 



While the Alcyonarians are seldom seen by the reef collector, 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. C. C. Nutting's reports on the 

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

 the first,-''- including the colonial forms, usually typified by the organ-pipe coral, 

 ai'e represented by only five species. 



Se.\-Pens and Sea-Pans. 



The order''' including the sea-pens and similar forms where the colonies 

 are arranged bilaterally and symmetrically on an axial stem, have sixteen 

 species in the off-shore fauna. The sea-fans, sea-plumes and their allies form 

 the most abuiulant order.-'^ Like llic otlii'i' orders of the class, they all have 

 eight-rayed polyjis. The beautiful horny tree or bush-like growth to be seen 

 in museums, however, gives but little idea of the appearance of the living 

 animal. Forty-eight species are included in the list of Hawaiian species, but 



=' Fiiiiniiilir. ^^ neiiilruiihWiu manni. '^ Sleaiulriua. '- Alri/rmai-ivr. '^i Pennatiilacea. 



