PART II.— ON HELIOPORIM] AND THEIR ALLIES. 



INTRODUCTION. 



This Part is mainly a reprint of a memoir on the same subject which was published 

 in the Philosophical Transactions for 1876 as a Preliminary Report on part of the 

 results of the Challenger Expedition. 1 The matter has been, however, rearranged; 

 some new terms have been introduced, and the discussion of the results attained 

 lias been modified in order to be in accordance with the facts concerning the Hydro- 

 corallinae which were ascertained by me since the paper was published. Certain 

 parts of the original paper relating to the structure of Millepora, Stylaster, and 

 Pocillopora have been omitted. 



I obtained specimens of the coral HeLiopora ccerulea in the living state at 

 Samboangan, in the Island of Mindanao of the Philippine group, in January 1875. 

 I examined the structure of the coral to some extent whilst in the fresh condition, 

 and made a further detailed investigation of its anatomy during subsecraent voyages. 

 For comparison I studied the anatomy of a species of Sarcophyton dredged in 

 shallow water amongst the reefs of the Admiralty Islands, and an account of the 

 structure of this Alcyonarian is given here at some length. 



Very little had been written on the structure of Heliopora ccerulea before the first 

 appearance of the present paper, and nothing further containing new information 

 has been added since. The previous accounts referred only to the structure of 

 the corallum or to the appearance of the living polyps, the latter being very 

 imperfect and unsatisfactory. They are referred to as occasion recpiires in the body 

 of the text. 



1 On the Structure and Relations of the Alcyonarian Hdiopora cozrulea, 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 Challenger 

 Expedition (Phil. Trans. Roy. Soc, vol. clxvi. p. 91, part 1, 1876). 



