240 FRESH WATER SPONGES OF NOVA SCOTIA—MACKAY. 
Genus IV.—TUBELLA. 
Statoblast spicules with a rotule on one end only of the shaft, 
or inequirotulate. 
9. LT. Pennsylvannica, Potts. 
Thin encrusting; rotule a very small circular entire disc, with 
the short central shaft attached on one side. Rare. 
two lakes in the East River basin. 
Found in 
Nore.—During the Summer 1885, the author extended the knuwn range of the most of these 
species to the lakes of Halifax County, Nova Scotia, and to the lakes of the Island of Newfound- 
fand. 
