138 Canadian Record of Science. 
vinia, or perhaps somewhat more advanced in complexity of 
structure, as these old forms of vegetation usually present 
types of structure in advance of those of their modern suc- 
cessors in the same groups. 
The specimens occur plentifully on the surfaces of a firm 
dark gray shale. They are perfectly flattened and carbon- 
ised, and so loosely attached that they can readily be re- 
moved, as thin pellicles, which when partially broken, often 
show their double walls. As opaque objects, under a low 
power they present a shining surface marked with cellular 
areolation. In this they resemble the Sporocarps of Proto- 
salvinia Braziliensis.1 When removed from the matrix, 
and immersed in water or in Canadian balsam, they become 
transparent, and show their thick-walled cellular structure 
very distinctly. The transparency is somewhat increased 
by boiling for a short time in nitric acid. 
There are two distinct forms on the surfaces of the shale 
—one, which is the more common, perfectly circular; the 
other, elongate obovate, and notched at the apex, sometimes 
so much as to give a bifurcate appearance. 
1.—Sporocarps of Protosalvinia Huronensis. 
These are the circular specimens. I refer them to this 
species, because its macrospores are the most common fossils 
of this shale, because they resemble those of P. Braziliensis, 
and because some of the specimens show impressions of 
contained macrospores similar in size to those of the species 
Huronensis. 
They are rather larger than the sporocarps of P. Brazili- 
ensis, some being four millimetres in diameter, They are, 
therefore, considerably larger than the sporocarps of the 
modern Salvinia of Kurope. In structure they are coarsely 
cellular, more thick-walled and larger-celled than those of 
P. Braziliensis, probably indicating a good specific differ- 
ence. Both of these ancient sporocarps are composed of 
coarser cells and more dense in texture than those of 
1 Record of Science, 1884. 
