CHAPTER XV.

The Triassic period--General characters and subdivisions of the Trias of the Continent of Europe and Britain--Trias of North America--Life of the period--Plants--Echinoderms--Crustaceans-- Polyzoa--Brachiopods--Bivalves--Univalves--Cephalopods-- Intermixture of Palæozoic with Mesozoic types of Molluscs-- Fishes--Amphibians--Reptiles--Supposed footprints of Birds-- Mammals--Literature.