566 Mr. H. N. Moseley on the true 



Besides Fungia symmetrica, the genera Caryophyllia, Flabellum, and 

 Cryptohelia are remarkable, but in a less degree, for their wide bathv- 

 metrieal range. 



Only about 27 genera of corals have as yet been proved to exist in a 

 depth of 250 fathoms and upwards. A list of these genera is here given 

 (p. 565), compiled from the reports of Count Pourtales and Prof. Martin 

 Duncan, and from my own notes. The various depths at which the genera 

 have been obtained are shown in columns. The letter A represents that 

 the coral was obtained by the U. S. Coast Survey at the stated depth, B 

 that it was dredged by H.M.S. ' Porcupine,' C by H.M.S. ' Challenger.' 

 In the last column S. denotes that the genus occurs in Secondary forma- 

 tions, T. in Tertiary beds. 



Geographical Distribution. 

 The extraordinarily wide distribution of Fungia symmetrica has alreadv 

 been referred to. Cryptohelia pudica occurs off the Canary Islands, off 

 the West Indies, off Bahia, in the South-west Pacific, and off the coast 

 of Japan. Flabellum apertum occurs off the coast of Portugal and off 

 the Marion Islands in the South-Indian Ocean. In this respect deep- 

 sea corals agree with almost all other deep-sea animals — the same forms 

 of starfish, sponges, Crustacea, &c. having turned up in the dredge over 

 and over again in all parts of the world from deep water with tedious 

 reiteration. Some deep-sea corals, however, appear, as far as our 

 present knowledge goes, to be remarkably limited in distribution, and 

 some groups to be specially developed in particular places. It is remark- 

 able that Pourtales does not record the occurrence of a single Flabellum 

 amongst the corals obtained by the IT. S. Survey. No Flabellum was 

 obtained in the corresponding region by the 'Challenger.' One appa- 

 rently abnormal specimen, here described as Flabellum angulare, was 

 obtained not far from Halifax, Nova Scotia, but none in the West-Indian 

 region. Various species of Flabellum have been dredged by the ' Chal- 

 lenger ' in deep water in all parts of the world, and two species were 

 obtained by the ' Porcupine.' It is further singular that only one 

 Stylasteracean was obtained, and at only one dredging, by the ' Porcu- 

 pine.' Pourtales describes seven genera of this group and eleven species 

 obtained from deep water, most of them from 270 fathoms, off Cuba, 

 where this group seems to be especially developed. We have dredged 

 specimens of the group at least eight times. A considerable number, 

 however, of the species of deep-sea corals dredged by us have been 

 obtained very seldom indeed and in few specimens, in several cases only 

 one specimen having been obtained. Thus of Trochocyathus coronatus 

 Pourtales received only one mutilated specimen from off the coast of 

 Florida, whilst we dredged five specimens on one occasion only off St. 

 Thomas. Of Ceratotrochus diaclema two specimens only have been 

 dredged at two localities in the Atlantic. Ceratotrochus platypus, C. dis- 



