President's Address. 9 
water fauna, in which certain types of life have a remarkably 
wide range in space. It must be observed, however, that 
some of these almost cosmopolitan types, such as the 
Graptolites, were almost certainly pelagic organisms, More- 
over, we have now distinct testimony to prove that the older 
Palzeozoic deposits of our existing continents are not all of 
shallow-water origin, as has been generally asserted. On the 
contrary, we have now definite evidence that rocks which 
may fairly be compared with the deep-sea deposits of the 
present day form part of various of the older Paleozoic 
formations in our existing land-masses, and thus mark the 
occurrence of oceanic conditions during these ancient periods 
in the areas now occupied by our continents. 
In the next place, we may consider the argument that the 
geological structure of our existing dry lands shows nothing 
to warrant a belief in anything more than local and partial 
submergences, to slight depths, in our present continental 
areas since the beginning of Cambrian time. In support of 
this argument, it is urged that the continents are mainly 
built up of marine deposits which are either of mechanical 
origin (sands, clays, etc.), and therefore deposited close to a 
coast-line, or are of organic origin (limestones), and were 
formed in water of moderate depth. It is also urged -that 
the marine formations of the continents, of all ages, are 
associated with lacustrine, estuarine, or. even terrestrial 
deposits, showing that the former were laid down in the 
vicinity of land. 
Now, so far as these arguments go to prove that the mass of 
the existing dry land is formed of materials which have been 
accumulated in seas of moderate depth, they may be freely 
accepted, and I do not suppose that any modern geologist 
would dispute them. At the same time, they neither dis- 
prove the past presence of genuine deep-sea conditions in 
areas now occupied by our great land-masses, nor do they 
necessarily prove that subsidence has always been “local” 
or “partial,” unless we are to give an exceedingly wide 
significance to these terms. 
Take, for example, the distribution of land and sea at the 
time of the deposition of the Upper Jurassic Rocks, as 
