Trochus. 57 
numerous one, consisting of more than one hundred 
species, which are scattered nearly all over the 
world, few seas being without some of them. They 
are found at various depths, from near the surface 
to forty-five fathoms down, creeping on rocks, sand, 
masses of sea-weed, etc. We will first speak of 
those found on our own shores, the two commonest, 
as well as the smallest of which, are the Grey 
and the Spotted Trochi, scientifically named J’. 
cinerarius and T. maculata, the translation of the 
first Latin specific name being ashy or ash-coloured, 
and that of the second, spotted. Trochus, in the 
same language, signifies a top, and has reference to 
the shape of most of these shells, which are some- 
thing like a boy’s whip-top. 
Children on the coast sometimes call the last- 
named of the above species Pepper-and-salt Shells, 
because in colour they resemble the cloth so named. 
The Muddy-red Trochus (2. ziziphinus), so called, 
perhaps, because in colour it resembles the ziziphia, 
or fruit of the jujube tree, is also common with us. 
This shell is about an inch long, of a grey tint 
dashed with dark spots, these follow the line of the 
spiral turnings, which are very regular, proceeding 
from the opening below to the apex or point. Seen 
on shore, its colours are dull and faint, but beneath 
