194 
MAJOR EARTH FEATURES 
islands, just as imperatively as does the immigration of the reptile 
fauna of the Keuper beds into the Late Triassic red beds of North 
America. 
Traces of such a land-bridge are present in that ridge [Wyville- 
Thomson ridge] which separates the Skandik of De Geer from 
the North Atlantic proper. This ridge is depressed below 500 
m. only in three small channels between the masses of the Shet¬ 
land Islands, the Faroes and Iceland, and in the Denmark 
straits.^^ The existence of a land-bridge until Mid Tertic time 
on the site of this ridge would serve to explain all zoogeographic 
relations between North America and Europe and between their 
bordering seas. For the acceptance of a North Atlantic continent, 
.in other words, of a union of Laurentia with Fennoscandia along 
a broad front, every convincing argument is lacking. 
As for the acceptance of an equatorial, or southern, continent, 
which in the first place was constructed to explain the spread of 
the Permian Glossopteris flora, I have already emphasized the 
fact that the difference of the land vertebrate faunas of Mesozoic 
time testifies against rather than for a union at that time of South 
America with Africa. The only argument that can be brought 
forth in favor of a union of both continents on a broad front is 
the spread of the Early Cretacic Uitenhage fauna of Cutch, 
India, southward along the coasts of the Strait of Mozambique 
[and across the South Atlantic] into the region of the Argentine 
Cordillera and as far north as Malone, Texas. The spread of 
this littoral fauna, characterized especially by peculiar groups of 
the bivalve genus Trigonia, could have taken place only along 
the coastal border of a continent, or an archipelago. As such, 
the coast of Antarctica suggests itself, since it approaches very 
near to South America through the Antarctic Cordillera, and 
through an archipelago which we may think of as including the 
Kerguelen, Crozet, and. Prince Edward Islands. It gives evidence 
of a land union which Ortmann also regarded as one of those 
still possible during Tertic time. 
A very strong argument against the acceptance of a broad 
continent bridging over the greater part of the South Atlantic 
23 Kontinentale Niveauveranderungen im Norden Europas: Petermanns Geog. Mitt., 
EVIII Bd., p. 122, 1912. 
24 Maximum depth 649 m. to the south of the Faroes. 
2B Map accompanying Reports of the Princeton University Expeditions to Pata¬ 
gonia, Vol. IV, Palaeontology, pi. xxxix, 1899. 
