NARRATIVE OF THE CRUISE. 



:;*:{ 



formed ; it is possible that the comparatively genial condition of the hind-locked fjords 

 and harbours of the Malvinas, and the additional shelter yielded by the imbricating fronds 

 of Macrocystis, may render such exceptional provision unnecessary. 



" Five at least of these directly developing Echinoderms representing five principal 

 divisions of the sub-kingdom, were dredged at the Falklands, and several others were 

 found earlier in the voyage in the sub-antarctic regions of the Southern Ocean. It will 

 perhaps give a better idea of the diversity of means by which practically the same end is 

 attained, if I give here a brief description of the principal modifications of the process 

 which were exhibited. 



Fig. 139. — Psolus ephippifer, 

 Wyv. Thorns, Corinthian. 

 Harbour, Heard Island. Three 

 times the natural size. 



Flo. 140. — 1'solus ephippifer, 

 Wyv. Thorns., some of the plates 

 of the marsupium removed. 

 Three times the natural size. 



" To give a second example from the Holothurioidea, on the morning of the 7th of 

 February 1874, we dredged at a depth of 75 fathoms, at the entrance of Corinthian 

 Harbour {alias ' Whisky Bay ') in Heard Island (so far as I am aware the most desolate 

 spot on God's earth), a number of specimens of a pretty little Psolus, which I shall here 

 call, for the sake of convenience, Psolus ephippifer, although it may very possibly turn 

 out to be a variety of the northern Psolus operculatus. 



"Psolus ephippifer (figs. 134, 135) is a small specie.-;, about 40 mm. in length by 15 

 to 18 mm. in extreme width. In accordance with the characters of the genus, the 

 ambulatory area is abruptly defined, and tentacular feet are absent on the upper surface 

 of the body, which is covered with a thick leathery membrane in which calcareous scales 



