Biological Stues in Madeira

Abstract

THE component islands and rocks on the Madeira Archipelago are separate foci of volcanic ejecta in the abysmal oceanic depths, and the level of the Atlantic waters might be lowered 100 fathoms without merging them in a common connexion. Of the 170 forms of Testacea existing in the region, only five species are distributed throughout the Island group, and such evidence is adversely copious and conclusive as to the theory that the Madeiras are a surviving relic of a former continent.