over 600 species, of which about 450 are not known to occur elsewhere, leaving 

 185 previously-known species.* 



Of these 185 species, that also occur in the depths of other seas, (a) thirty- 

 two, or 17 per cent, of them, belong to the true abyssal fauna more than 

 three-fourths of them coming from depths between 1500 and 1997 fathoms ; 

 (5) forty, or nearly 22 per cent, of them, probably belong to the nectic fauna ; 

 and (c) a hundred and thirteen species, or slightly over 61 per cent, inhabit 

 the moderate depths (between 1000 and 100 fathoms more than half of them 

 being found between 500 and 100 fathoms) of the slopes. 



It is to this last assemblage of species namely to the fauna of the 

 moderate depths, not far from the coast line, with which Flabellum laciniatum 

 and Caryophyllia communis are associated, that I wish to invite attention. 



fl. Regarding the excluded true abyssal fauna (1000-2000 fins.) of 

 these seas, however, I may mention that the 32 previously-described abyssal 

 species have the following faunistic relations : 



19 species or 59 per cent, occur in the abysses of the Pacific ; 

 10 ,, 31 Atlantic ; 



2 ,,6 both the Atlantic and the Pacific ; 



1 ,,3 Southern Ocean. 



I may further mention that of the ten Atlantic species, five are known 

 only from the depths off the West-Indies and the coasts of the United States 

 and Brazil. These five species are : 



Rorcellanaster caeruleus, Wyville-Thomson. \ 

 Pentagonaster intermedius, Perrier. > (Asteroidea). 



Nymphaster basilicus, Sladen. ) 



Pontopliilus abyssi, S. I. Smith, (Crangonidas). 

 Willemoesia forceps, A. Milne Edwards, (Eryontidffl). 



2. Regarding the excluded nectic fauna, I may explain that only the 

 following, among Indian forms, are counted : 



Gnathophamia, Eucopia, Thysanopoda, Bentheuphamia, Petalophthalmus ; 

 Hymenopeneus, Halipoms, Aristeus, Hepomadus, Benthesicymus, Gennadas, 

 Sergestes, Hoplophorus, Acanthephyra, Pasiphcea and Nematocarcinus, among 

 Crustacea ; Onychoteuthis, Calliteuthis, and Cirrhoteuthis, among the Cepha- 

 lopod Mollusca ; and Argyropelecus, Sternoptyx, Gonostoma, Chauliodus, and 

 Polyipnus, among Pishes. 



* Only the following groups have, up to the present, been named : Hexactinellid Sponges, Madreporaria, 

 Asteroidea, Ophiuroidea, Holothuroidea (partly), Echinoidea (partly), Stalk-eyed Crustacea, Mollusca, Fishes. 



Large collections of Octactinaria and Polychseta, aa well as small oolUctions of the other marine groups, are 

 still unnamed. 



