TWENTIETH ANNUAL REPORT 109 
Among the larger animals on exhibition may be mentioned 
porpoise, sea lion, sea turtle, alligator, crocodile, sturgeon and 
large jewfish—but the space that can be devoted to the larger 
forms is limited. 
The conditions for keeping fishes are on the whole quite 
good—but the same cannot be said of aquatic mammals and 
reptiles which need more light than the building affords. The 
mechanical equipment of the Aquarium has been much improved 
during recent years and the condition of the living exhibits is 
better than ever before. This is largely due to the improvement 
of the water supply in general. Losses of specimens have been 
greatly lessened, and it is no longer necessary to do the con- 
stant collecting from local and tropical waters that was formerly 
imperative. 
A porpoise (Tursiops truncatus) which had lived in the 
Aquarium for twenty-one months, was lost August 21. The cause 
of its death was a filth infection due to the foul condition of 
the water in the large pool where it was kept. Like the other 
large floor pools of the Aquarium it was filled with the sewage- 
laden water pumped from the Harbor. 
The new filters which have since been installed for the pur- 
pose of filtering the Harbor water should protect the animal 
occupants of the floor pools from such dangers in future. Not 
only does the water flow continuously, but the pools are lowered 
each evening and cleaned with long-handled brushes. The water 
is now quite clean and clear, but its salinity remains, of course, 
still very low. Bacteria are doubtless still present in this water, 
despite its improvement by the filtering process. 
The Zoological Society is indebted to the generosity of Mr. 
Joseph Keith Nye of New Bedford, Mass., for all porpoises of 
the genus Tursiops presented to the Aquarium. Mr. Nye is the 
proprietor of the porpoise fishery at Hatteras, N. C., and has 
offered to donate additional specimens. With his help the por- 
poise exhibit will be renewed and maintained. 
The porpoises lost during the summer from filth infection 
and others from injuries received at the time they were cap- 
tured, were by special request presented to the Wistar Institute 
of Anatomy in Philadelphia and to the Biological Department 
of Princeton University. 
