174 MYTILID^. 



the middle of the front of the shell, and furnished with 

 pinnated cirrhi in the branchial range. There are about 

 sixteen of these pinnated fringes which are usually, in 

 British specimens, of a yellowish white colour, though 

 sometimes, as well as the edges of the mantle, tinged with 

 brown, and in the foreign variety galloprovincialis they 

 are often deeply tinged with purple. The anal siphon is 

 very short, white, and equals half the breadth of the 

 branchial range ; its margins are quite plain. The foot is 

 dusky, narrow, strap-shaped and grooved ; from the basal 

 part of the groove the animal spins its byssus, which 

 is long, coarse, and of a yellowish brown colour. When 

 the byssus is broken away, another set of threads is readily 

 and often rapidly spun. The branchial leaflets are tawny, 

 elongated, nearly equal, and fi-ee at their lower edges. The 

 labial palps are also tawny, and of a triangular acuminate 

 shape, smooth on their outsides, and (as first observed by 

 Mr. Clark,) only partially pectinated on their inner sur- 

 faces. 



The common mussel is much used in many places for 

 food, and still more for bait. Dr. Knapp of Edinburgh 

 has communicated to us a very interesting account of the 

 quantities of this animal destroyed annually in the neigh- 

 bourhood of that city. " As an article of food," he states, 

 " there cannot be used fewer than ten bushels per week in 

 Edinburgh and Leith, say for forty weeks in the year, in 

 all 400 bushels annually. Each bushel of mussels when 

 shelled and freed from all refuse, will probably contain 

 from three to four pints of the animals, or about 900 or 

 1000, according to their size. Taking the latter number, 

 there will be consumed in Edinburgh and Leith about 

 400,000 mussels. This is a mere trifle compared to the 

 enormous number used as bait for all sorts of fish, especially 



