22 THE ELEMENTS 



Beak is the extreme point of the 

 summit of bivalves, which for the most 

 part points downwards, or to the one 

 side, as in most species of Venus, &c. 

 Plate 2nd, fig. 5th, rr. 



Seam. When the valves are closed, 

 the line between them is so called. 

 Plate 2nd, fig. 6th, tt. 



Umbo. That place situated imme- 

 diately under the beak. Plate 1st, 

 ^g. 6th, w ; and plate 2nd, fig. 4th, w. 



Ears. Two processes on each side 

 of the beak, in most of that division of 

 Ostrea, called scallops ; some have 

 one ear very large, and the other 

 small ; and some are scarcely observ- 

 able on one side. Plate 2nd, fig. 2nd, 

 hh. 



Superior Ear. Plate 4th, fig. 11th, 1i. 



Inferior Ear. Do. do. i. 



Margin, or Limb. The extreme 

 edge of the whole shell, or either 

 valve, all round. Plate 1st, fig. 4th, p ; 

 and plate 2nd5 fig. 1st, jt?. 



