THE BIOLOGY OF THE FUNAFUTI ATOLL AND KEEF FORMATION. 143 



(1) Porites limosa. A considerable block of this coral, which was dead at its base, 

 and could therefore be detached from the reef rock without in the least interfering 

 with the live portion, was secured by fastening it to a board, and then the whole was 

 lowered into about 3 fathoms of water at high tide, the same depth from which it was 

 obtained. The piece had been obtained near the spot where the experiments were 

 carried on. By means of a rope attached to a float the coral could be hauled to the 

 surface for examination whenever required. It, together with the board and attach- 

 ments, weighed, under water, 22 lbs. at the commencement of the experiment. At 

 every weighing both coral and board were scrupulously freed from the sediment, crabs 

 and molluscs, which were continuously settling on them. 



Throughout the four months during which this coral was under observation a steady 

 increase of weight, amounting to 47*27 per cent, per annum, was experienced.'^ 



(2) Hydnophora microcoria. This coral has a peculiar encrusting tendency and 

 is often found growing over dead portions of its own corallum. A piece well suited 

 for measuring purposes was discovered on the ocean platform near the drill camp. 

 The living coral was spreading from two sides over a dead piece. When first inspected 

 the two approaching sides were distant 3 thirty-seconds of an inch. After 55 days 

 they had met. If we assume that the two sides were approaching at the same rate, 

 growth to the extent of 1 inch in 39 months was indicated, f 



(3) AstrcBopora oceUata. A specimen of this coral was under observation. Certain 

 areas Avere jjinned out by means of glass pins so that any possible expansion might 

 be traced. Not the slightest increase in the areas was noticed. It was observed, 

 however, that new calicos were forming in the intervals between those already 

 existing Certain of these, while at first indicated by mere ^junctures, had after 

 three months attained very nearly to the size of the functional calices. This coral, 

 like, as it seems, all other forms, increases laterally in the shape of a thin expansion 

 at its free edge immediately where it overlies the dead foundation on which it grows. 

 Although this fact was noticed, measurements were unfortunately not taken. | 



(4) Pocillopora grandis. A young corallum of this species, about 2 inches in 

 diameter, was kej)t under observation in situ on the ocean platform. This specimen, 

 which is preserved in the collection, shows well the above-named method of 



■"■ The following are the details of this increase : — 



^ Weight, in lbs. 

 avoirdupois. 



August 1, 1898 22 



August 26, „ 23i 



September 9, ,, 23^ 



September 12, „ 23f 



October 8, ,, . . ' 24| 



November 14, ., 25 



t This specimen was preserved, and has been forwarded to London. 



I This specimen also was preserved, and has been forwarded to London. 



