8 



In our former account of this fiiell, it will be obferved 

 we had followed the example of greater naturalifls, by 

 placing it aniongfl the more fimplc univalve fliells. Recent 

 opportunity however, of more minutely inveftigating the 

 fubie6l, has clearly confirmed our former opinion, that if it 

 cannot flriclly be placed amongll the Pholadcs, if muft be 

 removed into the divifion of Multivalves. 



The larger valves, whicli cover une end of the animal, 

 are fimilar to fome fpecies of PJiolas ; and though deftitute 

 of any acccHory valve at the hinge, it is furnilhed with the 

 long curved tooth, ufually obferved in fhells belonging to 

 that genus. The acceffory or auxiliary valves of this are 

 placed at the oppofitc end, and in this particular only it 

 claims a feparate place, Thele four valves, which are at- 

 tached, and infeparably a part of the animal, conftitute it a 

 multivalve fliell, without confidering the cafe, or teftaceous 

 tube, formed by the animal for its better fecurity in its cell^ 

 as an aflual appendage ; for though it may be confidered as 

 a neceffary part in the economy of this animal, yet it is 

 wholly independent, and is no more than a padage formed 

 by the flimy exudation concreted into papyraceous lamince, 



thickening by age."* 



The 



* In llie Pliil. Trans, referred to, Mr. Home sajs there is an adhesion to the 

 cvHndrical shell at one spot, where the stems of the opercula (tlie lanceolate 

 Yulves) are connected with the animal. Whether such is accidental, or occasional 

 by means of any minute organs for that purpose, we cannot determine ; but tiiig 

 by our experience does not appear constant. In anotlicr place we have noliced 

 that Mt/u Pholadiu forms itself a similar testaceous case in stone; hut the uiiimal 

 has no attachmcDt to it. See Mi/a Pholadia. 



