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FRESH WATER SPONGES OF NOVA SCOTIA—MACKAY. 3 
Art. IX.—NOTES ON THE FRESH WATER SPONGES OF Nova 
scomma...-By A. H. MacKay, B.A. Bi Se 
WHEN examining the diatomaceous deposits of our lakes, we 
always found present in greater or less abundance the silicious 
spicules of fresh water sponges. In some of the material exam- 
ined there appeared to be even a greater amount of silica deposit- 
ed as sponge spicules than as diatom cells. A search for the 
origin of this spicular deposit, has revealed, up to date, the exist- 
ence of fowr genera containing nine species of fresh water 
sponges, which form a part of the living fauna of Nova Scotia. 
In the summer of 1884, in company with Hector McInnes, Esq., 
of the Pictou Academy, and John H. MacKay, Ksq., Principal of 
the River John High School, we made a most enjoyable explora- 
tion of the physical and natural history characters of the lakes 
in the basin of the East River of Pictou and beyond the water- 
shed of the Province on the upper sources of the St. Mary’s on 
the Atlantic slope. We constructed rafts when necessary, so as 
to be able to take soundings of their depths, and dredgings from 
various parts of their bottoms. This paper is simply an outline 
and classification of the species of spongillinma found on this 
expedition. 
Fresh water sponges are generally rather inconspicuous 
objects. The first reference to them in a printed work appears 
to have been made in 1696. Linnzus described two species in 
1745, under the names Spongia lacustris and S. fluviatilis. In 
1816 the name spongilla was given the genus by Lamarck. In 
1839, Meyen pointed out the peculiar spiculation surrounding 
the “seed-like” bodies of one of these two species (our 
Meyenia fluviatilis, see slides 26 and 27). In 1840 Hogg 
demonstrated that these “seed-like bodies” germinated and re- 
produced the spongilla. In 1867 Carter established the 
“animality” of these sponges. Lieberkuhn and Bowerbank, by 
aaeans of the spiculation of what the latter called “ovaries,” 
