84 JOURNAL AND PROCEEDINGS. 
and we may reasonably infer that the Laminarian Zone of olden 
times did not materially differ from the one of the present day. 
Bryozoan (Polyozoa) so abundant in the chert band of the Niagara 
Escarpment here, cannot be looked upon as safe guides in deducing 
geological conclusions regarding the depth of primeval seas. The 
modern Sea Mats, Mooses and ‘f Mermaids Lace Work ” are world- 
wide, inhabiting alike Arctic and tropical waters, attached to the 
floating Gulf weed (Sazgassum) and to the dense sea forests that 
annually spring up about Norfolk Bay and the shores of the North 
Pacific. Indeed, fossil plants, Algze or Fucoids, are not certain 
indicators on this point either unless undoubted evidence can be 
obtained that sea currents had not transported the broken sea weeds 
from a distant place. The Laminarian Zone is supposed to extend 
from low water to about fifteen or sixteen fathoms, but banks, etc., 
may occur a considerable distance from land and there the plants 
would flourish, no doubt, yet they are liable to be torn away from 
their anchorage in heavy gales and carried seaward, not shoreward. 
THE CHITON (MODERN COAT OF MAIL SHELL). 
I was recently asked when the above named shell first put in an 
appearance in a fossilized state. The late Professor Billings claimed 
he discovered a specimen in the Black River Series Cambro, Sil. 
He named it ‘‘ Chiton Canadensts.” 
Another was described by the late Dr. Salter, Palzeontologist of 
the Geological Survey of Great Britain and Ireland. It came from 
the Coal Measures, Europe, and was named Cf/iton Carbonartus. 
The former I have not seen figured or described, but little doubt 
can be entertained regarding the correct classification of the latter. 
We may see how very imperfect the geological Record must be 
when no specimens have been found in the intervening beds. The 
Devonian formation alone is nearly three miles in_ thickness. 
Dentatium, commonly called the Tusk Shell, is another Mollusc, 
which apparently survived from Palzozoic times. 
ANADONTA—UNIONID&. 
In “‘ Characteristic British Fossils,” of the late Professor W. H. 
Baily of Dublin, you will find figured the oldest fresh water bivalve 
I think yet discovered. It occurs in the upper part of the old red 
