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 (Tiosiops tntncatus) 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 

 off"ered 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. 



