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case the worms were dead, having been killed by the fresh-water. 
The mud contained in the blister-like cavities had become putrid, 
and its colour of an inky blackness, and the stench unbearable, 
In every instance where the mud was only covered by a thin 
deposit, the oysters were either dead or dying, from the attacks of 
the putrescent germs developed in the mud ; while those in which 
the deposit was thick appeared to be in a healthy condition. 
The worm does not seem to confine itself to the oyster ; I have 
seen it in Pinna Menkei and Pectunculus Dunkeri from 
Shoalhaven. It is common in Chione calophylla , Venus laqueata , 
and other bivales in Port Jackson. The distribution of the worm 
appears to be world- wide. It is found in Europe, North America, 
Australia, and the Philippine Islands. There is also a species 
described by Sehmarda from the Chilian coast of South America, 
which may prove to be the same. 
