401 



FIG. 589. PECTKN. 



ORDER II. PECTINID^. 



941. The PectenS) or Clams, are known by the regular radi- 

 ation of the ribs *from the summit of each valve to the circum- 

 ference; and by the two angular 

 projections, or ears, that widen the 

 sides of the hinge. The shell is 

 often very vividly coloured ; and 

 a marked difference in hue is fre- 

 quently observable between the 

 two valves. The animal has a 

 small oval foot ; and some species 

 are attached by a byssus ; whilst 

 others are said to swim freely 

 through the water by the flap- 

 ping of their valves, and can 



even regain the sea by a motion of this kind, when left upon 

 the shore. The large species upon our coast, Pecten maximus, 

 is the pilgrim's scallop shell, worn in front of the hat by those 

 who had visited the shrine of St. James at Compostella in Gal- 

 licia. Pectens are sometimes eaten ; but, as the animal is hard 

 and indigestible, few but the poor employ it as an article of food. 

 The hollow valve has been used as a dish ; and even as a culi- 

 nary vessel, being capable of bearing a considerable heat without 

 cracking. Among other genera of this family, we may notice 

 the Spondylus ; in which the shell bears a general resemblance 

 to that of the Oyster ; but the hinge is provided with two teeth 

 in each valve, which enter into corresponding depressions in the 

 opposite valve. The shell adheres to solid bodies of all kinds ; 

 and its form is modified by the surface of the objects on which 

 it grows. The animal is eaten like the Oyster. The most 

 interesting peculiarity in this genus has been already noticed 

 ( 870). Many of the species are of very vivid colours. 



