CORALS FROM MURRAY, COCOS-KEELING, AND FANNING ISLANDS. 



69 



In the following table the number of species given for each station repre- 

 sents the number actually submitted, plus certain interpolations. If a species 

 was collected at 800 feet and 1,200 feet from shore, but not at 1,000 feet, it 

 is added to the list of those from 1,000 feet, as not finding it at that station 

 was probably accidental. 



Distance from shore, depth of water, character of bottom, number of species, and grozvth-form 

 of the colonies, for each station on line I, southeast reef, Murray Island. 



Distance from shore. 



Depth of 

 water at 

 low tide 

 in inches. 



Character of bottom. 



No. of 

 species 

 at each 



No. of species accordmg 

 to growth-form. 



Fragile 



branches 



and free 



disks. 



Stout 

 branches. 



Massive 



or in- 

 crusting. 



300 feet 



400 feet 



450-550 feet . 



600-650 feet . 



800-820 feet . 

 1 000- 1 020 feet. 

 1200-1250 feet. 

 1400-1445 feet. 

 1600-1675 feet. 

 1 720- 1 775 feet. 



2 t 



4-5 

 6 



6.5 

 10 



14 



12 



14 



10 



4 



5 



12 

 10 

 II 



17 

 16 



IS 

 16 



Hard limestone mud over lava rock 



Firm limestone mud 



Sand and mud, rock 



Sandy 



Broken coral 



Rocky 



Rocky 



Rocky, broken coral 



Hard, rocky, broken coral 



Hard, rocky, with crevice-like tide 

 pools. 



7 

 10 

 18 



>20 

 21 

 18 



24 



32 



13 



3 

 3 

 7 

 6 



10 

 6 



10 

 4 



I 



4 

 7 

 II 

 12 

 10 

 10 



26 

 7 



^Acropora peciinata (Brook), which is of discoid-corymbose growth-form, is not counted in the tabulation. 



Although there are corals of massive growth-form up to within 300 

 feet of shore, and they somewhat preponderate in the number of species, 

 they reach their greatest development near the outer edge of the reef at 

 1,600 feet from shore and beyond, while the maximum number of species 

 with fragile branches is between 1,200 and 1,445 feet from shore, and there 

 is none on the exposed seaward face of the reef. These relations of growth- 

 form to position on the reef are dependent primarily on capacity to resist 

 waves and surf. Fragile corals would be smashed on the outer edge of the 

 reef. Massive as well as fragile forms may live in quiet water if sediment 

 should not be deposited on their surfaces more rapidly than it can be removed. 



OTHER CORALS COLLECTED NEAR MURRAY ISLAND. 

 Montipora raviosa Bernard was collected on line II, off the middle of 

 the northwest side of the island, at 150 feet from shore, on a firm sandy 

 bottom, covered with Posidonia and bare at low tide, and under a similar 

 environment on the same line, at 180 feet from shore; also on line III, off 

 the north end of the island, at 1,150 feet from shore, on a firm bottom of 

 mud and volcanic sand, covered with grass, and bare at low tide. This 

 coral has the same growth facies as Porites furcata and Porites divaricata, 

 which live under similar environmental conditions (protected shallow 

 flats, where there is often much grass) in Florida and the West Indies. 



