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PINNA. 
PINNA Auctorum. 
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OWE 5, Character Genericus. 
* 
Testa bivalvis Bata, cuneiformis, ad basin atte- 
nuata, antice hians, interne impressione unica, mus- 
culari, subcentrali: cardo i inermis ; ligamentum lon- 
gissimum, laterale. 
ANIMAL acephalum, byssoferum ; bysso sericeo. 
PINNA. 
GENERIC Cusnacren. 
Shell bivalve, elongate, wedge-sha ped, with the base 
attenuated, anteriorly gaping, internally with one nearly 
central muscular impression ;" hinge without, teeth; ligament 
lateral and very long. 3 
ANIMAL acephalous, furnished with: a silky beard. 
The animals of this genus, named in Bhat macres, sea- 
wings, or pinne marine, were celebrated among: the an- 
cients for the fine cloth manufactured from their beards, 
and on account of a little crab that was often. observed to 
inhabit their shells. This crab, named pinnotheres, was 
supposed to guard the pinna from the attacks of its ‘enemies, 
or to warn it of the entrance of little fishes within its gap- 
ing shells, by gently biting its side, on which the animal 
was believed to close its shells, and to sccure their mutual 
booty. No satisfactory reason has been assigned for the 
