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III. On the Structure of a Species of Millepora occurring at Tahiti, Society Islands. 
By H. N. Moseley, F.B.S., Fellow of Fxeter College , Oxford, Naturalist to the 
‘ Challenger ’ Expedition. Communicated by Professor Sir C. Wyville Thomson, 
F.R.S., Director of the Civilian Scientific Staff. 
Received March 6, — Bead April 6, 1876. 
[Plates 2 & 3.] 
In a paper treating mainly on the structure of the Heliopora caerulea, which was com- 
municated to the Royal Society in the autumn of last year (1875), I gave a short account 
of the results at which I had arrived from the examination of two species of Millepora 
obtained at Bermuda and at the Philippines, and expressed my intention of further 
prosecuting the subject at the Sandwich Islands and Tahiti, should material be forth- 
coming. 
At Honolulu no Millepora was met with ; and this form apparently does not occur at 
the Sandwich Islands, the water being too cold for it. At Tahiti a Millepjora is very 
abundant on the reefs in from one to two feet of water, and is very conspicuous because 
of its bright yellow colour. 
I failed in an attempt to procure the animals of this species in an expanded condi- 
tion ; but my colleague, Mr. J. Mukray, succeeded on two occasions, and on the second 
occasion showed me the expanded zooids, and handed the living specimens over to me 
for examination. I am greatly indebted to Mr. Murray for having thus afforded me 
the opportunity of studying the zooids of Millepora in the expanded condition, and I 
do not think that I should ever have succeeded in arriving at a satisfactory knowledge 
of their structure without this aid. Mr. Murray further, who had had better oppor- 
tunities of observing the living coral than I, first drew my attention to the fact that the 
central zooid of each system had a mouth. No species of Millepora appears hitherto 
to have been known to occur on the reefs of the Society Islands. In Dana’s work on 
Corals* no Millepora is mentioned as occurring at Tahiti, and this locality is not given 
for any species of Millepora by MM. Edwards and Haime. It is impossible to determine 
with any certainty the species of such a form as Millepora without access to museum 
collections. The Tahitian species, of which the structure is here described, resembles 
closely in form M. tuberculosa (M. gonagra) figured by MM. Edwards and HAiMEf. 
Like this species it never forms foliaceous expansions, but is tuberculate and irregular 
* United States Expl. Exped. vol. vii. Zoophytes, by J. 1). Dana. Philad. 1846. 
t Hist. Nat. des Coralliaires, pi. F3. figs. 1“, 1*. 
MDCCCLXXVII. S 
