92 The Amcncan Geologist. i>i>niary. i-.mm. 
moved shoreward upon a deepening of their former habitat 
when crustal shortening- or the slow folding of synclinal 
troughs, from sedimentation, occurred. 
While it seems naturally a fair speculation that the influ- 
ence of pressure would have upon developing molluscan or- 
ganisms the efifect of hastening their secretive functions, and 
that such influence might have been the original cause of 
establishing the shell forming habits of molluscan animals, 
we may further consider the thermal conditions of deep water 
in those early days. It must have presented sensibly high ther- 
mal phases, and, to quote Verworn, "everywhere in living 
nature the law is met with, that within certain limits increasing 
temperature acts to augment vital processes." 
This increase in temperature in the first days of oceanic life 
arose from the convexion of heat radiated from the coolin^f 
continental masses. The raising of lithic masses by contrac- 
tion must have imparted heat to the seas while indeed their 
bottom waters rested upon the cooled surfaces of an original 
cosmic fireball. It was such thermal conditions that directly 
contributed to an increase in the mineral constituents of the sea 
water, and might have in this way also hastened the develop- 
ment of shelly parts in sea animals. 
The Calciferous sandstone as revealed by Hall was a silice- 
ous shore deposit, and only the records made in the Champlain 
(Seely and Brainerd) basin display its unequivocal bathic fea- 
tures. The fossil remains present a cephalopodous and gas- 
teropodous fauna. Brachiopods of sensible dimensions and rep- 
resenting the articulate phylum appear, and we find that with 
the exception of corals and crinoids the palaeozoic biologic im- 
pulse has reached molar expression. The initial stages have 
been far passed. The divergences in genera and classes are 
thoroughly established. The partial introductory phase of the 
Cambrian day with its eccentric development of trilobitic 
forms and its thin shelled brachiopods has been succeeded by 
a multivarious and expounding series of organisms heavily 
armored in calcareous coverings. 
From this point onward throughout the palaeozoic series 
the application of the significance of Size and Skeletal Mass 
is generally evident. Let us consider the separate fossil 
groups. The inarticulate brachiopods present noticeably lar- 
