1 38 Cruise of the "Alert" 



Group," of which the survey commenced by the Chilians was 

 as yet incomplete. Port Riofrio is situated on the eastern side 

 of Wellington Island, and derives its name from a large moun- 

 tain torrent which pours its water into the bay nearly opposite 

 to the entrance, for which it also forms one of the principal 

 leading marks. On the western side of the anchorage, and form- 

 ing a sort of mighty dam across the valley through which this 

 torrent flows, is a remarkable raised beach, whose brow stretches 

 horizontally from ridge to ridge, its continuity being only broken 

 by a narrow fissure through which the torrent rushes, descending 

 thence by a series of cascades to the sea. Inside this barrier 

 the land slopes gradually but slightly downward to an extensive 

 plateau, which forms the bed of the valley between the two moun- 

 tain ranges. Opinions differed on board as to whether this 

 barrier was a raised beach or an old terminal moraine ; but I 

 inclined to the former view, from the fact of its brow being so 

 regular and horizontal, from its stretching evenly from hill to hill, 

 from the absence of any vestige of lateral moraine on the hill- 

 sides, and from the slight difference in actual level between the 

 brow of the barrier and the general surface of the plain within. 

 It was covered with the usual swampy soil-cap, and the plain was 

 for the most part occupied by an extensive swamp. Here I 

 collected fine fruiting specimens of a handsome velvety moss, 

 Tetraplodon mnioides, of a rich green colour, which I have before 

 alluded to as forming curious tufts on the summits of boulders, 

 on rocky pinnacles, and on the stumps of dead trees. 



On the shores of this anchorage grew several plants which we 

 had not previously seen in the Straits. Among these was the 

 Mitraria coainea, a climbing shrub, easily recognised by its dark- 

 green glossy ovate-acute leaves, and short tubular scarlet flowers. 

 Another was the Weinmannia trichosperma, a tall erect shrub with 

 serrated pinnate leaves, and jointed petioles winged in a curious 

 rhomboidal fashion. I was in hopes of finding here the beautiful 

 Hymenophyllnm cruentum, which we obtained last year at an island 



