10 Proceedings of the Royal Physical Society. 
worked out by Neumayr. It may not be asserted that the 
details of this distribution are in all respects accurate—in 
the nature of the case they cannot be so—but the data 
already in our possession leave little doubt as to the approxi- 
mate general correctness of Neumayr’s sketch of the geography 
of the world at this period of geological history. At this 
time three main masses of continental land appear to have 
existed. One of these—the “ Nearctic” continent—repre- 
sented the North America of to-day, but stretched eastwards 
to Greenland and Iceland. A second—the “ Brazilian- 
Ethiopic” continent—embraced almost the whole of South 
America and Africa, being continuous across what is now 
the South Atlantic, and sending up a long north-eastern 
prolongation through Madagascar to become connected with 
Southern India. A third—the “Sind-Australian” continent 
—included a large tract of South-Eastern Asia, extending 
from Noithern China through Siam and the great islands of 
the Indian Archipelago to New Guinea, Australia, and New 
Zealand. In addition to these primary land-masses, a great 
continental island (the “ Scandinavian Island”) occupied the 
region of Sweden, Norway, Finland, and adjoining districts ; 
and a second (the “Turanian Island”) occupied a con- 
siderable area round the Sea of Aral. Lastly, scattered 
islands of various sizes eccupied what is now Central and 
Southern Europe. 
Correlative with these changes in the distribution of the 
great land-masses, we find great differences in the dis- 
tribution of the marine areas of the Upper Jurassic. The 
Arctic Ocean of this period was enormously extended, 
covering the greater part of Siberia and large portions of 
North-Western America, and being directly and extensively 
continuous with the Pacific. The deep basin of the South 
Atlantic had no existence, but was occupied by the central 
portion of the Brazilian-Ethiopic continent. Lastly, the 
present Mediterranean was represented by a great meridional 
“Central Mediterranean” (the “Tethyan Ocean” of some 
geologists), which stretched across the mid-Atlantic, and 
became continuous with the Pacific to the west, the Carrib- 
bean and Central American areas being now submerged. At 
