217 
of some Corals from Fiji. 
name S. raristella , var. wilsoni, after the gentleman, who besides 
sending the specimens is largely responsible for the information 
about Levuka harbour. The variety differs from the type in 
having the ring round the calicle less distinct, but crowned with 
the six large spines of the primary septa, generally six smaller 
intermediate spines, and often six or twelve of a third order, no 
trace of any corresponding septa however beyond the first order 
being ever visible. The calicles tend to be disposed in series, 
which do not lie necessarily in any determinable direction in 
respect to the branches ; on the tips of the latter the series are 
ordinarily especially marked, crossing them in parallel rows. The 
coenenchyma varies considerably, but is fairly well developed, 
and covered with low pointed spines ; the calicles of a series at 
the tip of a twig generally have a common theca between, but 
below all tend to be separated by a breadth of about their own 
diameter (1 mm.) from one another. Often a row of spines divides 
the coenenchyma markedly between two separate calicles, or two 
series. The septa have smooth edges, and fuse below with the 
columella. The latter is always distinct above, projecting freely 
generally to the level of the top of the “ bourrelet ,” or rim round 
the calicle. 
Two of the other specimens evidently belong to the same 
species, which I referred to Pocillopora suffruticosa Verrill, in 
describing my collections from the Pacific Ocean 1 . The identi- 
fication down to the species is however uncertain at present, but 
it serves to indicate that the specimens belong to the finely 
branching division of the genus, noted also for its dense corallum. 
The last specimen may be provisionally referred to Pocillopora 
plicata (Dana) ; it is too small to determine properly its mode of 
growth, but it approaches close to var. aspera (Verrill)' 2 . 
In any discussion of the rate of growth of corals the volume 
of the specimens must be considered rather than the weight, since 
according to all my observations the density of all forms of a 
single species varies inversely with the rate of growth ; the slower 
the latter may be, the denser and heavier is the corallum, volume 
for volume. In the appended table I give the particulars of the 
rate of growth of the five specimens. In the third column I 
record the weights of the colonies, when they first arrived in this 
country, about three months after being obtained, to show by 
comparison with the fourth column the additional loss by thorough 
drying. In the last column I give the thicknesses of the coralla, 
1 P. Z. S.y 1897, p. 943. 
2 P. Z. S., 1897, pp. 947 — 8. In looking up this reference I find that I fell into 
error in calling P. aspera the type. It is indeed the central form round which the 
varieties are grouped, but according to the recognised rules of nomenclature the 
type should be P. plicata and the three varieties var. danae , var. ligulata , and var. 
aspera. 
