THE 



VOYAGE OF H.M.S. CHALLENGER. 



ZOOLOGY. 



REPORT on certain Hydroid, Alcyonarian, and Madreporarian Corals pro- 

 cured during the Voyage of H.M.S. Challenger, in the Years 1873-1876. 

 By H. N. Moseley, M.A., F.R.S., Fellow of Exeter College, Oxford, late 

 Member of the Civilian Scientific Staff of the Challenger Expedition. 



GENEEAL INTEODUCTIOK 



At the time when the Challenger Expedition set sail, very few investigations concerning 

 the anatomy of the soft tissues of stony corals had been made for a considerable number 

 of years. A large number of naturalists had failed to accept as conclusive the late 

 Professor Agassiz's results as to the hydroid nature of the Milleporid.e ; the Stylas- 

 terid.*; were universally considered to belong to the Madreporaria, although Gray had 

 formed them into a special family, and Pourtales and Verrill had recognised some of the 

 remarkable peculiarities of these corals. The presence of " tabulae " in Helioporo had 

 led to the association of that form with Millepora, and no one suspected that it was an 

 Alcyonarian allied to Corallium, Tubipora, and Alcyonium. 



When I undertook the investigation of the deep-sea Madreporaria dredged during 

 the voyage, I naturally became anxious to examine the structure of Millepora, and 

 early in the expedition attempted to make out the anatomy of Millepora alcicorn is at 

 Bermuda, but without much success, the problem proving too difficult, I did not succeed 

 with Millepora until near the end of the voyage. The discovery which I made at the 

 Philippine Islands, that Helioporo. is an Alcyonarian, led me to examine the structure of 

 all corals which were not most evidently Madreporarian, and hence I studied Stylaster, 



(ZOOL. CHALL. EXI\ — PART VII. 1880.) G 1 



