282 SUPPLEMENT ON MOLLUSCA. 
The figures of bivalve shells include, 
1. Cytherea lutea (Venus chione, Lin.) i a normal or per- 
pendicular position. 
2. Back view of the same in the same position. 
3. Interior view of the right valve of the same, in the same 
position. 
4, Exterior view of the left valve of the same, in the posi- 
tion of Linnzus and Lamarck. 
The letters A and P in each figure indicate the anterior 
and posterior parts of the shell, L and R the left and right. 
The figures of multivalve shells include, 
. Interior of the right valve of Pholas dactylus. 
. Left view of Pholadidoides Anglicanus. 
. Teredo nigra, De Blain., with a portion of the animal. 
. Posterior extremity of Teredo navalis. 
. Articulated palette of a Teredo. 
6. Balanus (Lepas, lin.) tintinnabulum. U.S. V. upper 
side valve, L.S. V. lower side valve. 
7. Operculum of Balanus squamosus. 
8. Left view of Polylepe vulgaris, Blainy. D. back, or 
dorsal valve; V. belly, or ventral valve. 
9. Upper view of Lepas diadema. 
10. Valves of Chiton squamosus. 
11. Valves of Chiton raripilosus. 
oOo fk W NO — 
le mga * _ 
— a 
a 
