KERGUELEN ISLAND. 27T 
On this island-plateau we have (1) a narrow weather-beaten shore, 
that is for the most part represented by a basaltio ledge, and only 
here and there, as at Accessible Bay, expands into a broader beach ; 
(2) a zone of red Floridew, that occupies the interval between this first 
ledge and a second which juts out immediately below it at a depth of 
one to two fathoms; (3) next in order, and four to six fathoms deeper 
down, is a broader “laminarian” zone, where a forest of Macrocystis 
grows rooted to basaltic blocks lying loose in mud. These submerged 
terraces, which are simply the lower members of the basaltic steps 
that reach to the flat-topped summits of the hills, are smoothed away 
to a more gradual slope in the various fjords, where a sandy beach 
passes gradually at about twenty paces from the shore into the black 
basaltic mud. (4) Lastly, we have the great muddy area of the 
plateau itself, the mud being intermixed to a very large extent, and 
more and more as we recede from the island, with the siliceous 
remains of Diatoms and Hexactinellids. 
1. In the first area, the narrow tidal tract presents a poverty- 
stricken fauna. On the rocks are clusters of small mussels, ascribed 
by E. A. Smith, Studer and others to Mytilus edulis, L., but by Dall 
to M. canaliculus, Hanley. They deserve to be collected in quantity, 
here and elsewhere ; for the Mytili of Chile, the Falklands and New 
Zealand are all closely allied, and offer, as indeed they do in all other 
seas, an interesting problem in variation. The soft parts also should 
be preserved, for in the Southern form they are said by Dall to differ 
from our Northern one, though this is in turn denied by Smith. 
Attached to the byssus of these mussels is a minute bivalve described 
by Dall as Kidderia minuta, n. g. et sp., but referred by Smith to 
Modiolarea, extremely like Modiolarca pusilla, Gould, from Tierra del 
Fuego. Creeping among the rocks is a large Siphonaria, S. redim- 
culum, Rve., closely allied or identical with 8. tristensis, Leach, from 
Tristan d’Acunha, and found also in Patagonia and the Falklands. 
Near low-water mark lives Trophon albolabratus, Smith, a form closely 
allied to T. philippianus, Dunker, from the Straits of Magellan, Cape 
Horn and the Falklands, and still more closely to 7. cinguliferus, Pffr., 
from 8. Georgia. Next we have a singular little shell identified by 
Dall with the almost world-wide Laswa rubra, but on the other hand 
referred by Smith to Kellia, and described, under the name of 
K. consanguinea, as closely akin to K. miliaris, Phil., from the 
Straits of Magellan. Lastly, we have a very interesting and peculiar 
Chiton, Hemiarthrum setulosum, Dall, and a Doris not described 
in detail, but probably identical with Archidoris kerguelensis, Bergh. 
Within reach of the tide we have also two land-shells, Hydrohia 
