MYTILUS. 291 



ralistj and serve to embellish the drawing-room and library. 

 Persons of taste admire their tintings and construction ; yet 

 the formation of the inhabitants is still more worthy of re- 

 gard than the exquisite variety of the floatiDg citadels in 

 which they are enclosed. Those valves, which are frequently 

 so remarkable, close and open according to the necessity or 

 inclination of the occupant, and this is effected by means of 

 a fleshy protuberance of a reddish hue, divided into two 

 lobes, and answering the purpose of feet. When, therefore, 

 a Mussel is incHned to leave his station, the shell is gradually 

 opened by the help of this strange member, which, assuming 

 a new form, pushes forward, and makes a furrow in the sand, 

 into which the shell is drawn in a vertical position. Trom 

 this position he almost immediately changes into his former 

 horizontal one ; the member shovelling back the sand, and 

 lengthening the furrow, while the animal journeys on his 

 way with a motion which causes a continual inversion of his 

 shell. Tracks, formed most probably by Mussels in quest 

 of food, may be readily observed on the sand, where these 

 creatures abound after the tide has run out : they resemble 

 small furrows, but are rarely straight ; deviating into mazes 

 and triangles, like the course of a vessel when contending 

 with adverse winds. 



u 2 



