10 
THE GEOLOGIST. 
tlie then extension of the sea over those districts in which onr 
most flourishing cities now exist — the sites of London, Paris, 
Berhn, Milan, Florence, Rome, Naples, Madrid, &c., were all 
submerged, as also the present situations of the most lofty moun- 
tains, such as Mont Blanc. A vast extent of land existed in 
Scandinavia — the gulf of Bothnia was not formed — Denmark, 
Hanover, Prussia, and Poland did not exist ; hut Silesia, Mora- 
via, Bohemia, Saxony, Hesse, Rhenish Prussia and Belgium 
formed an extensive island in the midst of the ocean. The 
boundary of this island extended from Arras to Treves, forming 
tw^o large promontories, including the Vosges and Black Forest, 
Batisbon, Vienna and Cracow, where a strait existed with a north- 
westerly bearing. Another promontory, very irregular in ap- 
pearance, existed in the centre or south-east of Prance, joined by 
a very narrow isthmus to the Pyrennean district, which even then 
appeared, only in a very much less elevated character. Autun 
w^as on the sea-side, and the site of Lyons, although submerged, 
was situated near the shore together with Perpignan. A small 
island occupied the site of Toulon, and Corsica existed at no 
great distance. To the west the land extended from Poictiers, 
past Angiers, Cherbourg, Liverpool to beyond Edinburgh — the 
channel was not then in existence, and Ireland was united to 
this great continent. 
The ocean which surrounded these islands possessed its pecu- 
liarities also. The Spiriferse and Producta had long since dis- 
appeared, and several species of Terebratulse were the only rem- 
nants of the tribes inhabiting the former seas. Chambered 
shells (ammonites) then appeared for the first time, belemnites 
also appeared, as well as marine sam'ians and Pterodactyli ; it 
was during this period also that those extensive coral beds ex- 
isted, which have subsequently been traced in the coral rag for- 
mation. 
Lakes and water-courses existed in the extent of land which 
favoured the growth of Paludina, and those species of Helix 
which we find in the Portland oolite. 
