124 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
and connecting channels vary from forty-eight to ninety feet and 
depths of seven and eight fathoms occur in the Rio Valdivia opposite 
the town. While glacial gravels and boulders not far inland as at 
Llanco Station show the presence of Pleistocene glaciers or glacio- 
natant waters, I noted no distinct signs of glacial erosion of the 
channels about Valdivia. It seems to me more probable, therefore, 
that these depths indicate a depression of the coast since the formation 
of the terraces rather than that they are due to glacial erosion inde-- 
pendently of the sea-level. 
Below the fifty-five to sixty foot level, I noticed a small terrace on 
Teja Island opposite Valdivia at a height about twenty-five feet 
above sea-level, but this was not elsewhere observed except possibly 
as noted below. 
Along the coast south of Corral entrance near Palo Muerto Pt., 
there are several ancient sea-caves not now visited by the sea at high 
tide. Near them is a trace of a bench at about 22 feet. The mouths 
of these caves are not over ten feet above sea-level (Plate 33). The 
bottoms of the caves are covered with a fine dusty cave-earth which 
covers any pebble bed which may occur on their bottoms. One of 
the caves (Plate 33) had been at the time of my visit recently occupied 
by natives and a heap of shell refuse formed a considerable mound at 
the entrance. In the same vicinity at Morro Gonzales there is a 
natural bridge in the rock of the sixty foot terrace formed by a cave 
penetrating to a small ravine in the rear. In front of the caves at 
a few points where the coarse Tertiary conglomerate is developed 
there is a flat or bench, cut back across these rocks, whose surface is 
at least partly covered by high tide. It is evident that a slight 
relative rise has taken place removing the caves from the action of 
the sea, but while this may have been as much as ten feet it may not 
have been over five feet as the depth of cave-earth would seem to 
show. In embayments south of Corral entrance, there are old beach 
ridges the highest of which comes sharply against the ravined surface 
of the land behind it. The uppermost of these ridges agrees well with 
the level of the mouths of the caves and does not indicate a rise of 
more than ten feet and possibly not more than five feet above sea- 
level; but, as Suess has pointed out, on the west coast of South 
America beach ridges may be thrown up by seaquake waves or 
tsunamis above the normal marine limit and thus are to be taken with 
caution. 
At Talcahuano and Concepcion. The literature concerning eleva- 
tion about the Bay of Concepcion relates largely to the discussion 
