326 ON A SPONGE DESTRUCTIVE TO OYSTER CULTURE, 



ON A SPONGE DESTRUCTIVE TO OYSTER CULTURE 

 IN THE CLARENCE RIVER. 



By R. von Lendenfeld, Ph.D. 



I was lately instructed by the Commissioners of Fisheries, to 

 report on a sponge injurious to oyster culture in the Clarence 

 River. Some of the facts noticed in this report are here men- 

 tioned, as I think they will be of general interest. 



The locality which was affected and which I was to rej)ort iipon, 

 I did not personally visit, and the information and specimens on 

 which my report was founded were derived entirely from Mr, 

 Woodward, the intelligent lessee of the oyster beds in question. 



The whole nearly of that part of the bed of Clarence River, which 

 is situated in proximity to a lake, and also a portion of the lake 

 itself, was covered five years ago by an extensive oyster bed. 



In a small portion of this area, where the river jo ns the 

 lake, four years ago an overgrowth made its appearance, which 

 smothered all the oysters and prevented the setting of the spat. 

 Consequently no oysters have been procured from tiiis area during 

 the last few years, whilst formerly the same area yielded, as I have 

 been informed, thousands of sacks. The lessee ascribed this to the 

 existence of the overgrowth mentioned above. 



I have examined specimens of it, and have found that it is a 

 sponge belonging to a species nevv to science. The sponge grows 

 on the outer side of oyster shells, which in that locality form the 

 bottom. 



The sponge consists of numei^ous flattened, finger-shaped pio- 

 cesses joined at the base to form a bulky mass. The color is light 

 brown. The size of the largest specimens seen by me is 7" x 3" x 4". 



The finger-shaped processes attain a length of 4" and a diameter 

 of f of an inch. They terminate either with a rounded cone or 

 show a tendency to bifurcation near the termination. 



