On Eozotin Canadense. 353 
we have as yet revealed to us the life of only certain stations in 
the Laurentian seas. 
fi 
ogebigains of the fine tubulation of the original cell-wall, which 
u 
been filled up by the infiltration of a mineral different from that 
of which the shell is composed, and therefore not coalescing with 
it; and the tubular structure is consequently much more satis- 
factorily distinguishable. In decalcified specimens, the free mar- 
gins of the casts of the chambers are often seen to be bordere 
with a delicate white glistening fringe; and when this fringe Is 
examined with a sufficient magnifying power, It 1s seen to D 
made up of a multitude of extremely elicate acicult, standing 
side by side like the fibres of asbestos. These, 
the internal casts of the fine tubuli which perforated the proper 
surface: and their presence i this situation affords the most sat- 
isfactory contention of the evidence of that tubulation afford- 
ed by thin sections of the shell-wall.” 
“The successive layers, each having its own proper wal — 
i of the Nummuline ake one 
deposit of thi f shell-substance, readily distinguishable Dy 
i = Aerie Tar orang ee the finely tubular shell pan gg 
investing the segments of the sarcode-body, is the source 
