128 Prof. M'Intosh on the 



Further, the slightly pelagic Ophiopleron of Amboyna, one 

 of the Moluccas, is not so widely distributed as some other 

 types devoid of such an apparatus for progression. 



The distribution of the Ccelenterates, such as zoophytes, 

 jelly-fishes, sea-anemones, corals, and sea-fans, presents 

 special features, for some are more purely tropical, others 

 more characteristic of the colder areas, whilst not a few — like 

 Campanularia^ Obelia, and Eudendrium — are cosmopolitan. 

 Thus the coral-reefs are tropical and subtropical, yet some 

 stony corals, such as Lophohelia and Caryophyllia, occur 

 in temperate seas. The jelly- fishes and sea-anemones are 

 cosmopolitan, though some, like Cestus, are characteristic of 

 the warmer seas. Alcyonarians range from tropical to cold 

 regions, those in the former, however, according to Prof. 

 Hickson, being distinguished by the abundance of their 

 spicules or by massive skeletal structures. 



Sponges are often widely distributed, some forms being 

 common to the North Atlantic and the Cape, others to the 

 latter and Australia ; whilst European types range to South 

 Africa and America. 



The Foraminifera, Radiolarians, and other types of the 

 Protozoa (e. g. JSocliluca) have an extensive distribution, 

 the former ranging from the Arctic to the borders of the 

 Antarctic Ocean, and forming vast deposits in many areas. 

 The distribution of Noctiluca and the pelagic forms like 

 Ceratium is equally wide ; nor is there any hard-and-fast 

 line separating the distribution of families or larger groups 

 from each other. 



In connexion with regional distribution in the ocean, it 

 has been supposed by some that the fauna of the deep water 

 (abyssal region) is peculiar, but many families found there 

 have representatives in shallower water and even between 

 tide-marks. Thus amongst the deep-water fishes the Murge- 

 nidse include the eels so common between tide-marks in the 

 Channel Islands and elsewhere. The Clupeidse comprise 

 the herring, sprat, and anchovy — widely distributed pelagic 

 fishes which come near the shore to spawn. The Ophidiidae 

 are almost universally spread from Greenland^ to New 

 Zealand, and the family includes the sand-eel of our shores. 

 In the same way the Pediculati, another family of deep-water 

 fishes, has a representative, viz. the frog-fish, in shallow 

 bays. A considerable number of Mollusca are also inhabi- 

 tants of the depths of the sea, but representatives of the 

 same families or even genera occur in shallow water; and 



