SHORES OF THE CLYDE AND FIRTH. 
139 
the top end of the foot is the bottle-nosed head, with its 
mouth opening and closing, and showing the same silicate 
rasp as his black brother — being also a vegetarian. Down 
at the nape of the neck are another pair of feelers, more 
muscular than the others, and which, in this case, may be 
termed the horns. These, however, unlike the horns of the 
former, are destitute of eyes; but close by the roots, one 
on each side, we discover these orbs perched upon the top 
of two little flesh-coloured stalks. 
Turning now to the shell itself, we see the turbanated 
form overcast with a dark purple coating ; and shining 
through this are the grey lines of the ground beneath, 
which shew in the dead shell cast up on the beach a beauti- 
ful silvery appearance. But turning up the mouth, we see, 
at its entrance, the enamel of the interior, whose shining 
pearly lustre vies with the tints of the rainbow. Looking 
at the edge of the operculum^ or lid, we notice a small hole 
leading into a cavity in the middle of the shell ; and tracing 
this cavity we find it a complete cone, piercing through and 
through. 
To give the reader an idea of the work this little creature 
has to perform in building himself a house to live in, we 
will endeavour to illustrate. Suppose, then, we set a child's 
trumpet on end, and, beginning at the top, twist a turban- 
shaped chamber, open at the inner edge, round the structure, 
widening as it goes till it ends at the base in an oblong, 
horn-shaped mouth, and we have a very fair notion of the 
performance. But what is the use of the cone-shaped 
cavity 1 it will be asked. Well, the designer saw it was 
needed. Tracing the cone to the top, we see that near this 
point it communicates with the interior chamber, and now 
we find it is the storehouse for the secretions of the creature 
through which the matter passes. 
