i86 



NA TURE 



[7 an. 3, ,1878 



appearance from the illustration. The special volume in 

 which the whole group of these lily-like starfish will be 

 described is, we understand, to be from the pen of Sir 

 Wy ville Thomson. 



Though the zoological treasures obtained by dredging 

 were often very great, yet sometimes this often prolonged 

 operation ended in utter disappointment ; for example : — 

 The vessel was on her way from Bahia to the Cape, when, 

 on October 2, " we saw our first albatross sailing round the 

 ship with that majestic careless flight which has been our 

 admiration and wonder ever since ; rising and sinking, and 

 soaring over us in all weathers, utterly regardless of the 



Fig. 



^.—Claaodactyla crocea, Lesson. Stanley Harbcur, Falkland Islands, 

 Natural size. 



motion of the ship, and without the slightest apparent 

 effort. I have often watched these glorious birds for hours 

 from the bridge, and notwithstanding all we know or think 

 we know about the mechanics of flight, to the last I felt 

 inclined to protest that for so heavy a bird to support 

 itself motionless in the air, and perform its vigorous evo- 

 lutions without a perceptible movement of the wings, was 

 _ simply impossible by any mechanical means of which we 

 have the least conception. 



" On the 3rd we sounded in 2,350 fathoms with a 

 bottom of red mud, still due apparently in a great degree 

 to the South American rivers, and a bottom temperature 

 of o°'8 C. The trawl was lowered, and on heaving in, it 



came up apparently with a heavy weight, the accumula- 

 tors being stretched to the utmost, it was a long and 

 weary wind-in, on account of the continued strain ; at 

 length it came close to the surface, and we could see the dis- 

 tended net through the water ; when, just as it was leaving 

 the water, and so greatly increasing its weight, the swivel 

 between the dredge-rope and the chain gave way, and the 

 trawl with its unknown burden quietly sank out of sight. 

 It was a cruel disappointment — every one was on the 

 bridge, and curiosity was wound up to the highest pitch ; 

 some vowed that they saw resting on the beam of the 

 vanishing trawl the white hand of the mermaiden for 

 whom we had watched so long in vain ; but I 

 think it is more likely that the trawl had got 

 bagged with the large sea-slugs which occur in 

 some of these deep dredgings in large quantity, 

 and have more than once burst the trawl net." 



Among the interesting creatures met with living, 

 not in the depths of the sea, but in this instance 

 living amid the fronds of one of the larger algae, 

 was a Holothuroid, of which we have the following 

 account : — 



" The weather while we were at the Falklands 

 was generally cold and boisterous, and boat-work 

 was consequently uncomfortable and frequently 

 impracticable, except in the shallow water within 

 the harbour ; we had, however, two or three days' 

 dredging in the pinnace, and made a pretty fair 

 account of the submarine inhabitants of our 

 immediate neighbourhood. Macrocystis pyrifera, 

 the huge tangle of the Southern Seas, is very 

 abundant in Stanley Harbour, anchored in about 

 ten fathoms, the long fronds stretching for many 

 yards along the surface and swaying to and fro 

 with the tide. Adhering to the fronds of ma- 

 crocystis there were great numbers of an elegant 

 little cucumber-shaped sea-slug {Cladodactyla 

 crocea, Lesson, sp.), from 80 to 100 mm. in length 

 by 30 mm. in width at the widest part, and of a 

 bright saffron-yellow colour. The mouth and 

 excretory opening are terminal ; ten long, delicate, 

 branched oral tentacles, more resembling in form 

 and attitude those of Ocnus than those of the 

 typical Cucutnarice, surround the mouth; the 

 perisom is thin and semi-transparent, and the 

 muscular bands, the radial vessels, and even the 

 internal viscera can be plainly seen through it. 

 The three anterior ambulacral vessels are approxi- 

 mated, and on these the tentacular feet are 

 numerous and well developed, with a sucking-disc 

 supported by a round cribriform calcareous plate, 

 or more frequently by several wedge-shaped radiat- 

 ing plates arranged in the form of a rosette ; and 

 these three ambulacra form together, at all events 

 in the female, a special ambulatory surface. 



" The two ambulacral vessels of the * bivium ' 

 are also approximated along the back, and thus 

 the two interambulacral spaces on the sides of 

 the animal, between the external trivial ambulacra 

 and the ambulacra of the bivium, are considerably 

 wider than the other three ; consequently, in 

 a transverse section, the ambulacral vessels do 

 not correspond with the angles of a regular pentagon^ 

 but with those of an irregular figure in which three 

 angles are approximated beneath and two above. In 

 the female the tentacular feet of the dorsal (bivial) 

 ambulacra are very short ; they are provided with sucking-, 

 discs, but the calcareous support of the suckers is very 

 rudimentary, and the tubular processes are not apparently 

 fitted for locomotion. In the males there is not so great 

 a difference in character between the ambulacra of the 

 trivium>nd those of the bivium ; but the tentacles of the lat- 

 ter seem to be less fully developed in both sexes, and I have 

 never happened to see an individual of either sex progress- 

 'ing upon, or adhering by, the water- feet of the dorsal canals. 



