THE DEVONIAN AGE. 87 



consideration a group of beds very dissimilar from 

 that which he would have to study on the shores of 

 Lake Erie. But here again identity of relations to 

 the Silurian below and the carboniferous above, 

 shows the contemporaneousness of the beds, and this 

 is confirmed by the occurrence in both series of some 

 of the same plants and shells and fishes. 



It will further be observed that it is in the 

 middle that the greatest difference occurs. Sand and 

 mud and pebble-banks were almost universal over 

 our two great continental plateaus in the Older and 

 Newer Devonian. But in the Middle there were in 

 some places deeper waters with coral reefs, in others 

 shallow flats and swamps rich in vegetation. Herein 

 we see the greater variety and richness of the De- 

 vonian. Had we lived in that age, we should not 

 have seen great continents like those that now exist, 

 but wo could have roamed over lovely islands with 

 breezy hills and dense lowland jungles, and we could 

 have sailed over blue coral seas, glowing below with 

 all the fanciful forms and brilliant colours of polyp 

 life, and filled with active and beautiful fishes. 

 Especially did all these conditions culminate in the 

 Middle Devonian, when what are now the continental 

 areas of the northern hemisphere must have much 

 resembled the present insular and oceanic reigons 

 of the South Pacific. 



Out of the rich and varied life of the Devonian I 

 may select for illustration its corals, its crustaceans, 

 its fishes, its plants, and its insects. 



