kelp. These species are the commonest now living on this coast. The shells
all appeared very old; the blue of the mussels was much faded; and only
traces of colour could be perceived in the Patellas, of which the outer
surfaces were scaling off. They lay scattered on the smooth surface of the
gravel, but abounded most in certain patches, especially at the heads of
the smaller valleys: they generally contained sand in their insides; and I
presume that they have been washed by alluvial action out of thin sandy
layers, traces of which may sometimes be seen covering the gravel. The
several plains have very level surfaces; but all are scooped out by
numerous broad, winding, flat-bottomed valleys, in which, judging from the
bushes, streams never flow. These remarks on the state of the shells, and
on the nature of the plains, apply to the following cases, so need not be
repeated.

(DIAGRAM 4. SECTION OF PLAINS AT PORT S. JULIAN.

From East (sea level) to West (high):
Terrace 1. Shells on surface. 90 Est.
Terrace 2. 430 An. M.
Terrace 3. 560 An. M.
Terrace 4. 950 An. M.)

Southward of Port Desire, the plains have been greatly denuded, with only
small pieces of tableland marking their former extension. But opposite Bird
Island, two considerable step-formed plains were measured, and found
respectively to be 350 and 590 feet in height. This latter plain extends
along the coast close to Port St. Julian (110 miles south of Port Desire);
see Diagram 4.

The lowest plain was estimated at ninety feet: it is remarkable from the