Note 2607 — BOOK IX. THE NATURAL HISTORY OF FISHES.

Ajasson says, that the words “purpuras, conchylia,” here signify not the fish themselves, but the various tints produced by them; the purpura and the conchylium being, in fact, exactly the same fish, though, as will be explained in c. 60 of the present Book, by various modes of treatment, various colours were extracted from them. See also B. xxi. c. 22.