Madsen J.F. On the zoogeography and origin of the abyssal fauna in view of the knowledge of the porcellanasteridae

By F. Jensenius Madsen
Zoological Museum. Copenhagen
Introductory remarks
Historical steps in the exploration of the deep-sea fauna
The delimitation of the abyssal region
The bathymetrical range of the Porcellanasteridae
The mode of life of the Porcellanasteridae
The geological age of the Porcellanasteridae
The interrelationships of the porcellanasterid genera
The geological age of the deep-sea
Life conditions in the ancient and in the recent deep-sea
The theoretical composition of the deep-sea fauna
The geological age of the recent deep-sea fauna
The alleged antiquity
The Mesozoic and Early Caenozoic elements
The Late Caenozoic elements
The factors deciding the vertical zonation of the deep-sea fauna
Some characteristics of deep-sea animals
The horizontal distribution of the abyssal fauna
The cosmopolitanism
Some cosmopolitan species
EKMAN'Sco nsiderations on a possible cosmopolitanism of the abyssal fauna
The main subdivision of the lower abyssal fauna
The "guests" in the abyssal region
Commentary on N.G.Vinogradovav'iSe w on the abyssal zoogeography
Possible explanations for an Atlanto-Indian and a Pacific (East Pacific) abyssal
fauna element respectively
The alleged endemism in the trench faunas
The distribution of the abyssal fauna in relation to the condition of the bottom
The possible fluctuations in the abyssal populations