ETHERIA, 



he the egg's of some molluscous animal, so frequently seen 

 on fresh water shells; but Lamarck says that they are 

 attached to the rocks at a considerable depth in the sea, on 

 which account they are little known, having escaped the 

 observation of collectors. 



Lamarck mentions singular bubble shaped, unequal 

 swellings in the interior, but which appear to him to be 

 accidental ; these are very conspicuous in the lower valve 

 of the specimen from whi^ch our drawing is taken, we think 

 they are caused by the accidental introduction of little par- 

 cels of sand over which the animal, to obviate the inconve- 

 Biences their presence causes, has deposited a coat of shelly 

 matter. He also speaks of an oblong callossity, which is as 

 it were incrusted in the base of the shell without forming 

 any internal projection. 



Not known in a fossil state. 



The specimen from which our plate is drawn is in the 

 possession of the Rev. Dr. Goodall, Provost of Eton College, 

 &c. We have represented the iiisjde pf both valves^ and 

 the outside of the upper one. 



