REPORT ON CORALS — HYDROCORALLIN^E. 33 



The coenostea of several species of the family have been known to science from early 

 times. The earliest known species, according to MM. Milne-Edwards and Haime, seems 

 to have been Stylaster Jlabell 'i/ormis, the Corail blane of Seba (Thesaurus, iii. 204, pi. ex. 

 fig. 10, 1758), whde Stylaster roseus and Distichopora violacea were described under the 

 general genus Madrepora, by Pallas, in 1766. 



Gray gave the name Stylaster to the genus in 1331 (Zool. Miscell., p. 36), and 

 described the genus Errina in 1835 (Proc. Zool. Soc, 1835, p. 35). Distichopora was 

 named by Lamarck, Allopora by Ehrenberg in 1834, and Cryptohelia was described by 

 MM. Milne-Edwards and Haime in 1849. 



Pourtales has added a new genus to the family, viz., Pliobothrus, as one of the results 

 of the United States' deep-sea dredging operations, and Saville Kent another, Stenohelia, 

 whilst I have added five genera, viz., Sporaclopora, Spinopora, Conopora, and Astylus, 

 dredged by H.M.S. Challenger, and Labiopora, wrongly described by Gray as a Bryozoon 

 under the name Porella. 



Dr Edward Graffe of Zurich found a species of Distichopora living at Fiji. It grows 

 only on the outermost reef border of Ovalau Island, close to the surf, attaching itself in 

 dark hollows in old dead Madrepore blocks. It never grows in the light, and is rapidly 

 bleached by the action of sunlight. Griiffe observed the large round cells in the 

 ampullae, and conjectured that they were ova, but he could not obtain a view of the 

 zooids, although he examined specimens brought fresh from the sea. He concluded that 

 Distichopora was probably a Bryozoon. 1 



The only extant account of the soft parts of any Stylasterid is that of the animals 

 of Allopora norwegica by G. 0. Sars. 2 



Sars kept a succession of living specimens of the coral in fresh sea water, but never 

 got the animals to expand so as to raise themselves above the level of the stellate 

 openings. Nevertheless he saw clearly with lenses the tips of the opacpue white tentacles 

 in the angles between the so-called incomplete septa, which tips were usually more or less 

 bent inwards towards the centre. He also saw deep down in the bottom of the calicle a 

 similarly opacme white knot-shaped projection. This was all that could be seen in the 

 fresh living animals. Specimens were, however, preserved in spirit and subsequently 

 examined, and the conclusion was come to that the animal was essentially different from 

 the rest of corals, and probably did not belong to the Anthozoa at all, but rather to the 

 Hydrozoa. 



By means of lucky breakings through of the stony-hard but nevertheless porous coral, 

 Sars was able to obtain some little view of the general form of the polyps and their 



1 Dr E. Graff e, Notizen iiber die Faime cler Viti Inseln. Verh. unci tier K.K. Zool. Bot. Gesell in Wien, xvi. 

 Bel., 1866, 1585. 



2 G. 0. Sars, Bidrag til Kundskaben om Dyrelivet paa vore Havbanker. Forh, i Videnskabs Selskabet, i 

 Christiana, 1872, p. 115. 



(ZOOL. CHALL. EXP. — PART VII. — 18S0.) G 5 



