nces of walls built by human hands,
with regular layers of stones, and which traverse the ravines of the
island in all directions.

As might be expected, I found regular basaltic crystals in this valley,
and also a variety of quartz ore, and other crystals, in the veins
traversing the basalt. I also found the following remarkable section:

This was in a side valley or ravine leading from Gregory's Valley in a
southerly direction.

On going down to the sea I found many species of starfish. I brought away
three species of these with me. Two Species Pentagonal; one species
Quadrilateral.

First species Pentagonal length of side 0.55 inch.
Second species Pentagonal length of side 0.50 inch.
Quadrilateral length of side 0.55 inch.

I found a sort of worm in the coral which had the power of extending its
head like an English worm; its body then appeared to be composed of two
portions, the fore part being much slighter than the other. Its
dimensions were:

Length of fore part of body 0.4 inch.
Length of hind part 0.6 inch.
Breadth, or diameter of cylinder 0.1 inch.

In the coral there was also another insect, not unlike a centipede.

Length 0.9 inch.
Breadth at head 0.08 inch.

In the inmost recesses of the coral there was a minute bivalve shell and
also a very minute species of crab.

One remarkable circumstance relating to St. Helena is that it is of a
basaltic formation exactly resembling that of the Isle of France and the
North-west of New Holland; and that, although so widely separated in
longitude, these places lie in nearly the same latitude.

When you quit the sandstone ranges of the North-west of Australia
reptiles which have been before very numerous at once become scarce. I
never saw a snake in this great basaltic district although there were
plenty in the sandstone. This however is only negative evidence. Brookes,
in his History of St. Helena (second edition page 24) says: "There are
neither frogs, toads, nor snakes in the island." In the Isle of Bourbon
there are neither toads nor snakes. In the Mauritius likewise there are
neither toads nor snakes, and only one species of frog, whilst the bones
of the land tortoise (Testudo indica) are only found in a fossil state.
Also, the highest land in St. Helena is 2800 feet; in the Mauritius about
2900 feet (scarcely); and in the volcanic district of North-west
Australia about the same height.

July 26. At sea.

We caught a great variety of shrimp-like a