Among other curiosities — or, as I prefer to regard them, weighty and suggestive 

 facts — of geographical distribution, must be mentioned that of the singular Amphihelia-like 

 Eupsammid Dendrophyllia (Coenopsammia) profunda, which was discovered by Pourtalès in 

 deep water among the West Indian Islands, ancl which we now find flourishing in the depths 

 of the Sea of Banda, in proximity to two other strange Oculina-like Eupsammids. This species 

 has also, quite recently, been discovered by the "Investigator" in deep water off Ceylon. 



The cosmopolitan Bathyactis symmetrica Pourtalès is of course present in the collection, 

 and also illustrates its well-known elasticity of bathymetric range, having been dredged at the 

 one extreme in 289 metres (Station 12) and at the other extreme in 18S6 metres (Station 208). 



The almost infinite adaptability to pressure conditions of Bathyactis symmetrica Pourtalès 

 is shared by its congeners Bathyactis stephana, which ranges from 69 to 1301 metres, and 

 Bathyactis Siöogac, which ranges from 522 to 19 14 metres. Deltocyathus lens, a small new 

 Turbinoloid species, can accomodate itself with almost equal ease, having been dredged, on 

 the one hand, at 390 metres and, on the other hand, at 4914 metres. 



Four other peculiarly adaptable species, which show the transition between the deep-sea 

 and what I propose to call the deep prope-littoral zone, may here be mentioned. The)- are 

 Deltocyathus magnificus Mosely (522 to 15 metres), Tropidocyathus lessoni Michelin (390 to 

 69 metres), Trochocyathus caryophylloides (304 to 15 metres), and Flabellum distinctuin E. & 

 H. There are no hard and fast boundary-lines in Nature, and I do not think that the extensive 

 bathymetric range of any of these species invalidates the distinction, emphasized in this Report, 

 between the veteran fauna of the deep sea. and the recruiting ground of the prope-littorBl zone. 



The southern end of the Sulu Sea seems to be one of the richest places in the world 

 for deep-sea corals. At seven stations close together, between the parallels of 5 43' and 6° 15' N. 

 and the meridians of ii9°4o' and 12 1° 28' E. and the depths of 270 and 1270 metres, no 

 less than 32 species representing 18 genera were dredged by the „Siboga". At one single 

 station of these seven (Station 95, 522 metres) 22 species of 14 genera came up at one haul. 

 Hardly less fertile is the neighbourhood of the Kei Islands in the Banda Sea, where the 

 "Siboga" dredged many of the species described by Moseley from the "Challenger" collection. 

 When it is remembered that some of these teeming coral-grounds support prolific branching 

 forms like Amphihelia, we may well imagine that in the depths of some of the tropical seas 

 actual submarine coral-reefs may be forming. This idea is supported by the facts mentioned in 

 the Report on the "Investigator" deep-sea Madreporaria, that at a depth of 430 fathoms off 

 the Malabar coast nearly half a ton of deep-sea corals were brought up at a single haul of 

 the dredge ; and that at a depth of 1000 fathoms, in the Laccadive Sea, over two hundred 

 specimens of a large species of Caryophyllia were netted in a haul of no long duration. 



Xo tremendous hauls of this sort appear to have been made in the course of the 

 "Siboga" expedition, but, on the other hand, the basins explored by the "Siboga" are vastly 

 richer in species than the depths of the seas of the western part of the Oriental Region 

 explored by the "Investigator". 



