MARINE BIOLOGICAL STATION AT PORT ERIN. (i 
of “Boreal Outliers”? or assemblages of northern species 
occupying the deeper areas of about 80 to 100 fathoms that 
occur here and there on the West Coast of Scotland. Such 
molluscs as Puncturella noachina, Trichotropis borealis, Natica 
groenlandica, Astarte elliptica, Nucula pygmaea, Emarginula 
crassa, Pecten danicus, Neaera cuspidata, and the brachiopods 
Terebratula caput-serpentis and Crania norvegica,* are charac- 
teristic forms in these boreal outliers, and Forbes’ view was 
that they were a part of the original northern fauna which 
formerly occupied our seas and which had retreated northwards 
when the climate became more genial subsequent to the glacial 
epoch, leaving these colonies isolated in the deeper holes. 
Some of the chief conclusions, to which the facts and 
arguments stated in his detailed memoir lead, he summarises 
as follows :— 
‘“‘(1) The fauna and flora, terrestrial and marine, of the 
British Islands and seas have originated so far as that area 
is concerned since the Miocene epoch. 
(2) The assemblages of animals and plants composing 
that fauna and flora did not appear in the area they now 
inhabit simultaneously but at several distinct points of time. 
(3) Both the fauna and flora of the British Islands and 
seas are composed partly of species which appeared in that 
area before the glacial epoch, partly of such as inhabited it 
during that epoch, and in great part of those which did not 
appear there until afterwards. 
(4) The greater part of the terrestrial animals and flowering 
plants now inhabiting the British Islands arose outside that 
area and have migrated to it over continuous land. 
(5) The Alpme floras of Europe and Asia are fragments 
of a flora which was diffused from the North. The deep sea 
fauna is in like manner a fragment of the general glacial fauna. 
(6) The termination of the glacial epoch in Europe was 
* T have given throughout the names as used by Forbes. 
