.3^. THE ''ALBATROSS" EXPEDITION. 451 



they are distinctively and entirely volcanic, and have never been 

 connected with the mainland of South America, from which they are 

 now separated by a wide plain nearly 2,000 fathoms in depth. 



The observations upon the deep-sea fauna are most important 

 and interesting. The "Challenger" Expedition traversed the centre 

 of the Pacific Ocean, along a line extending through the Sandwich 

 Islands to Tahiti. The " Albatross " examined a wedge-shaped portion 

 of the wide expanse lying to the eastward of this line. One of the 

 most striking facts elicited was that there exists in this area a 

 ** considerable fauna, which finds its parallel in the West Indies, and 

 recalls later Cretaceous times, when the Caribbean Sea was practically 

 a bay of the Pacific." 



Some differences may be noted — in the Pacific area the scarcity 

 of Ophiurids contrasts strongly with their abundance in the Atlantic, 

 *' where it often seems as if ophiurans had been the first and only 

 objects created." 



The general absence of Crinoids and Cotnatula was noticeable, 

 although one very inreresting new genus iCalamocriims) was obtained 

 from 782 fathoms off Mariato Point, an elaborately illustrated 

 description of which has already been published.^ 



Among Bryozoa further examples of the interesting genus Kine- 

 toskias, first obtained by Danielssen off the Norwegian coast, and 

 subsequently by the " Challenger " at several localities in the Atlantic 

 Ocean, have been dredged. 



Several Acalephs [Atolla, Periphylla), certain Beryx-\\ke fishes, 

 Scopelids, Stomias, Melamphaes, must now be excluded from the 

 abysmal fauna in which they have hitherto been reckoned, as they 

 have been captured by the Tanner net in depths less than 300 

 fathoms. 



A brief comparison is presented to us of the relations existing 

 between the Echinoid fauna of the two sides of the Isthmus of Panama, 

 with a promise of a more detailed statement hereafter. Only one 

 genus of urchins (Salenia) has been discovered in the deep waters of 

 the Pacific side which has not previously been found on the Atlantic 

 side. The interesting Echinothurids appeared, but these, as is well 

 known, have an extensive Pacific as well as Atlantic distribution. 



An important feature of the work on board the " Albatross " 

 was the number of coloured sketches prepared by the artist, Mr. 

 Westergren, Some of these have reached this country, and will be 

 most useful in supplementing descriptions of specimens preserved in 

 spirit. 



A considerable amount of information is given in the present 

 Report regarding the colours of various deep-sea types ; these are 

 very variable, but there seems to be a preponderance of violet. 

 In many cases there seems to be a great lack of adaptation to the 



1 See Natural Science, No. 2, p. 93. 



2G 2 



