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I V. On the Structure and Relations of the Alcyonarian Heliopora cserulea, with some 
Account of the Anatomy of a Species of Sarcophyton, Notes on the Structure of 
Species of the Genera Millepora, Pocillopora, and Stylaster, and Remarks on, the 
Affinities of certain Palaeozoic Corals. By H. N. Moseley, M.A. Oxon., Naturalist 
to the 4 Challenger ’ Expedition. Communicated by Professor Wyville Thomson, 
F.R.S., Birector of the Civilian Staff of the 4 Challenger.' 1 
Received September 28, — Read November 25, 1875. 
Introduction. 
Haying undertaken the examination of the Deep-sea Corals dredged by the 4 Challenger’ 
during her voyage, my attention was naturally directed to the study of the structure of 
corals generally. The Milleporidse, both because of their peculiar tabulate structure 
and relations to fossil forms, and because of Prof. Agassiz’s well-known determination of 
them as Hydroids and not Actinozoa, seemed to offer the most interesting field for in- 
vestigation ; and I accordingly commenced the examination of their structure very early 
in the cruise of H.M.S. ‘Challenger’ in April 1873, at Bermuda, where Millepora 
alcicornis occurs in great profusion. 
I made a number of preparations and made out some points in the anatomy of this 
species, but found the subject to be so difficult that I put the matter aside to be further 
examined on reaching England. In the beginning of 1875, however, I obtained speci- 
mens of Heliopora coerulea in the living state at Zamboangan, and on examining these 
found to my astonishment that Heliopora was an Alcyonarian. I therefore during 
subsequent voyages made as complete an examination as possible of this species, and 
examined for comparison with it the structure of another Alcyonarian, a species of 
Sarcophyton dredged in shallow water amongst the reefs of the Admiralty Islands. I 
examined further the structure of a species of Millepora obtained at Zamboangan ; and 
I also examined a Pocillopora found at the same locality, and a species of Stylaster 
dredged in 500 fathoms off the Meangis Islands. The results form the substance of the 
present paper. 
Recent Literature concerning Tabulate and Rugose Corals and Alcyonarians &c. 
I am able to refer to very few original papers relating to the present subject, but 
have gathered the following from the more general works available on board the 
4 Challenger.’ It is hoped that allowance will be made for the peculiar conditions 
under which this paper is written. 
M. Milne-Edwards (Hist. Nat. des Coralliaires, Paris, 1860, t. iii. p. 224) forms the 
MDCCCLXXVI. O 
