UNIVALVES. 137 
or thick glue is obtained, resembling soft wax; but 
the purple dye is situated in the throat, and that of 
the finest hue, in a small white vein. The chief 
riches of Nicoya consist in these shell-fish. They 
are used in dyeing the cloth of Segovia, which is often 
sold for twenty crowns the ell; as the wearing of it, 
is entirely confined to nobles of the highest rank. 
The coasts of the South Sea, near the equator, in 
the neighbourhood of point St. Helena, in the pro- 
vince of Guayaquil, also furnish some shell-fish of a 
similar description, which are termed by Don Antonio 
de Elloa, sea-snails. They adhere to such rocks and 
stones as are covered by the sea at high water, and 
are about the size of small nuts, containing a liquor 
or juice, which has the true colour of purple. This 
colour is very bright, and so durable, that washing 
rather increases than diminishes its lustre; nor does 
it experience any perceptible alteration in conse- 
quence of use or wearing. 
The Carribbee Islands have likewise their purple 
fish, which resemble our perriwinkles. The shell is 
of a brownish azure —the flesh white, and the intes- 
tines of a bright red, the colour of which appears 
through the body. On being taken from the water 
the creatures exude a considerable quantity of froth, 
which is received on a linen cloth, and becomes purple 
as it dries, 
