239 
The Nomenclature/’ which is inserted imme- 
diately after the Introduction/’ refers to the 
Genei'ic and Specific Characters of Shells, among 
which Colours ought not, properly speaking, ever 
to be ranked : they distinguish varieties and indi- 
viduals which differ in the same species, and, being 
liable to uncertainty and change more than any 
other feature, are to be considered as the last in 
value. To the last place, therefore, they have 
been consigned in the present work, which has 
been arranged as much as possible upon the re- 
gular gradation necessary to the description of any 
subject of Natural History, according to the spirit 
of the Linnsean System. 
In the following list those colours only are enu- 
merated, which occur in the Latin descriptions of 
Testacea. The name of a well known pigment, or 
some other permanent standard, is affixed to those 
respecting which there can be any doubt. Where- 
ever the termination ish is used, it implies that an 
inconsiderable portion of the colour tinges white, 
or enters into combination with the other men- 
tioned ; — as redd^s/^ yellow, signifies that yellow 
is the principal, and red but a small ingredient in 
the hue. , . 
