358 SUPPLEMENT 
we are forced to pass in silence many subdivisions of the 
mollusca, even when some degree of popular interest may 
attach to them; but it would be unpardonable to omit all 
mention of the animal supposed to have produced the cele- 
brated purple of the ancients. 
M. de Lamarck was the first who established under the 
name of PURPURA, a distinct genus composed of several 
species of shells, previously classed by Linneus and his fol- 
lowers, in the genera buccinum and murex. The name, 
however, was applied before by various authors, not only to 
the species of the last mentioned genera, but to many others, 
owing doubtless to this circumstance, that all these animals 
furnish in greater or less abundance, the materials which the 
ancients employed in dyeing. In fact, we must not even sup- 
pose that it is in the species of this genus that the purple is 
principally found. It exists equally in murex and buccinum, 
and it is even probable that the species of shell-fish, from 
which the ancients extracted the purple, did not belong to 
the present genus; this, however, is a convenient place for 
treating on the subject. 
The purpure are marine animals, living in the fractures of 
rocks, in places covered with fucus, and also sometimes bury- 
ing themselves in the sand. ‘They creep, by the aid of their 
foot, like the other gasteropods. Their nutriment appears to 
be constantly animal, and obtained by piercing the shell, 
principally of the bivalve mollusca. 
The mode of sexual intercourse is not known. The eggs are 
spheroid, a little elongated, corneous, of a yellowish colour, 
and not deposited until towards autumn. They adhere to the 
rocks, and other submerged bodies, by means of a sort of 
paste. Their other extremity is closed by a sort of opercle, 
small, oval, thick, and transverse. In their interior, a thicker 
matter is found in the middle of one more fluid. 
The species of this genus are found in all seas; but the | 
