[D17]

During Miocene or old Pliocene, climate apparently warmer than now, & yet many species of shells in common (when Miocene temp Flora very different & consisted of American plants) there could have been only a small polar country, (hence but few species) & these migrated southward either over land or by ice & occupied now temperate Europe or its islands, Faroe, Iceland & Greenland a desert (no peculiar species) must have been colonized subsequently; & from Europe as nearest country, & hence Baffin Bay stopped many plants hence Marten's facts about direction of immigration of plants. But migration of Birds wd. make one think that land once continuous.