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, 

 fig. 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, /*. 



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 2nd, fig. 1st, p. 



