54 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 
a Committee of the Royal Society, acting in conjunction with the Geo- 
graphical Society of New South Wales. A boring was made through the 
rim of the atoll and this eventually reached a depth of 1114 feet. 
The results of the inquiry are not yet published, but there is no doubt 
that they will be found to be of great interest and importance, both in 
connection with the question of the origin of coral reefs and also in 
their bearing on the formation of dolomite. 
Methods of collecting Specimens. — In the Funafuti Expedition a boring 
was made on the edge of the reef, and a vertical succession of specimens 
was thus obtained. In that case, if the boring was in solid reef through- 
out, the position of a particular specimen determined its age relatively 
to those above and below it. This method of collecting has the further 
advantage that where a gradual structural or mineralogical change occurs 
in the rock, the change can be closely followed by specimens at short 
intervals, but its great cost renders it of only limited application. In 
the case of collections from raised coral reefs much the same result was 
sought by collecting in vertical sequence from cliff faces, ravines, etc., at 
heights definitely ascertained by measurement or by the records of the 
aneroid barometer. 
During the upheaval of a coral island accretions to the older rocks 
occur, to a greater or less extent, in the form of fringing reefs, several 
of which are often found at successive heights on one island, marking 
pauses in the movement of elevation. Stalagmitic deposits and talus 
slopes also occasionally mask the true surface of a cliff face. On this 
account it is necessary to exercise great caution in collecting from raised 
coral islands to avoid the possibility of mistaking recent fringing material 
for the older nucleus of the island. This difficulty can usually be over- 
come by taking certain precautions which have been employed by the 
leaders of the expeditions mentioned below. 
It is often noticed that fringing reefs most commonly occur on the 
leeward side of an island; while on the windward side not only is no 
fringing reef formed, but the sea makes inroads into the older limestone, 
forming lines of beach-erosion at various heights. It is also found that 
in some of the islands examined’natural sections or ravines occur, and 
these often cut through any superficial material, exposing the older rocks. 
Advantage was taken of these natural features in making the collections, 
while Mr. E. C..Andrews took the additional precaution of blasting into 
the solid rock in making his collections from the Fijis. 
1 It would perhaps be better to use the term “negative movement of the shore 
line.” 
