CHAPTER XIII. 



THE MUSSEL. 



" Ecce inter virides jactatur mytilus algas." ANTHOLOGTA. 



1 HE MUSSEL is a well-known lamellibranchiate 

 mollusc, belonging to the family Mytilidw : 

 a family which includes the Sea Mussel, 

 Mytilus; the Pond Mussel, Anodontu; the 

 Mulete, or Painter's Mussel, Pina cardium ; and some 

 other genera. As the Mytilus is the object of an exten- 

 sive fishery, it requires and deserves description. 



Like the oyster, which it resembles in its general 

 organization, the mussel is an acephalous mollusc and a 

 bivalve. Unlike the oyster, it attaches itself to its 

 resting-place by an apparatus of threads, called the byssus, 

 which is secreted by a special gland. In shape it differs 

 greatly from the more popular mollusc, for it is longi- 

 tudinal, with a regular equivalve, and comparatively 

 smooth shell, pointed at the base, and of a bluish-black 

 colour. The hinge is without teeth, but the uniting 

 ligament is located in a deep furrow. 



The animal enclosed in this oblong equi valvular case 

 is elongate, and oval, witli the lobes of its pallium (or 



