made during the Voyage of H. M.S. ' Challenger.' 571 



more interesting animals which were got in the dredgings, so far as they 

 fall under the above-mentioned categories, then say something on the 

 surface-animals, and finally on the result of my excursions on shore. 



The Atlantic. 



Here and there on the coasts of the Atlantic deep-sea animals have 

 been found either washed on shore or floating dead on the surface of the 

 sea. Certain Crustacea and fish on the coasts of Madeira and the Medi- 

 terranean, Umbellularia and Cirroteuthis in the high north, were animals 

 considered very rare, and about the habitat of which nothing certain was 

 known. Much of this uncertainty has been cleared up by the three suc- 

 cessive English dredging-expeditions ; and I shall give at the end of this 

 report a short statement regarding those animals known before deep-sea 

 dredging began systematically. There is in the Atlantic only one place 

 in which Hyalonema had been of late years regularly found, and this was 

 considered to be a place, like Japan, where alone this sponge genus might 

 be procured. Since that time matters have greatly changed, especially 

 as far as the distribution of the glassrope sponges goes ; for now we 

 know that genera like Hyalonema, Euplectella, Aphrocallistes, Farrea, &c. 

 are the most characteristic inhabitants of the great depths all over the 

 world, and with them ordinary siliceous sponges, some of which rival the 

 Hyalospongiae in beauty. 



Umbellularia was found three times in the Atlantic after the Swedes 

 had rediscovered this genus, which nearly a century ago had been found 

 by a whaler on the coasts of Greenland. Professor Kolliker has already 

 worked out this species, which he considers to be different from the 

 northern one. Alcyonaria and Antipathes have also been constantly 

 brought up, and the latter is especially characteristic of great depths. 



We owe to American expeditions a good deal of what was known 

 about the bathymetrical distribution of corals and of Echinoderms ; but 

 especially the latter have during this 'Challenger ' expedition yielded a 

 very large variety of species, the greater part of which is very likely new 

 and has partly been described already by Professor Wyville Thomson. 

 I have been greatly interested in Crinoids for the sake of their parasites 

 (Myzostomum), most of which were, however, got only in the Pacific ; 

 and I shall say a few words about their very extraordinary mode of living 

 when giving an account of the worms found in that ocean. 



The Platodes are a group which has been rarely met with ; here and 

 there of course Cestodes or Trematodes in young or old stages might be 

 found inhabiting the invertebrates and afterwards the fish ; but nothing 

 has come to my knowledge about them, as the latter were far too precious 

 to be dissected for helminthological purposes. Nemerteans do go down 

 to great depths ; but they were rarely got here, only once off the coast of 

 Brazil, in 1200 fathoms ; and the worst is that when you do get them 

 they are generally in pieces, either by friction among stones and mud or 



