644 DESCRIPTION OF PLATES, 7 9. 



Fig. 6 a, Balanus amaryllis; 6 b, scutum, internal; 6 c, tergum, ex- 

 ternal view. 



7 a, Balanus allium; 7 b and 7c, scutum, external and internal 



views; / d, tergum, external. 



8 a, Balanus cepa, scutum, internal ; 8 b, scutum, external ; 8 c, 



tergum, external view. 



PLATE 8. 

 Genus — Balanus. 



Fig. 1, Balanus quadrivittatus. 



2 a, Balanus terebratus, part of basis seen from the outside ; 2 b, 



the same, seen from within. 



3 a, Balanus vestitus, scutum, internal view ; 3 b, tergum, external 



view. 



4 a, Balanus imperator, scutum, internal view ; 4 b, tergum, ex- 



ternal view ; 4 c, portion of basal edge of wall of the shell. 



5 a, Balanus flosculus. 



5 b, „ ,, var. sordidus. 



5 c, „ „ scutum, internal view. 



5 d, „ „ „ „ var. 



5 e and bf t ,, tergum, internal and external views of. 



6 a, Balanus bisulcatus, scutum, external view ; 6 b, tergum, ex- 



ternal view ; 6 c, scutum, internal view. 

 7, Balanus dolosus, tergum, external view. 



8 a, Balanus unguiformis, scutum, internal view ; 8 b, tergum, do. 

 9, Balanus varians, tergum, external view. 

 10 a, Balanus inclusus. 

 10 6, „ „ var. that has been attached to a branch of 



a coralline. 

 10 c, „ ,, „ seen from beneath, showing the narrow 



furrowed basis and wide lateral com- 

 partments; the other four compartments, 

 namely, the two carino-lateral, the carina, 

 and rostrum, being of very small size. 



PLATE 9. 



Sub-genus — Aca sta. 



Fig. 1 a, Acasta spongites ; 1 6, scutum, external view ; 1 c, scutum, 

 internal; 1 d, tergum, internal. 



2 a, Acasta sulcata ; 2 b, var., lateral compartment of ; 2 c and 2 d, 



terga, internal views of two varieties. 



3 a, Acasta cyathus ; 3 b and 3 c, scutum and tergum, internal 



views. 



4, Acasta undulata, scutum, external view. 



5 a, Acasta glans, basis seen from within ; 5 b, compartments of a 

 smaller specimen, seen from within ; carina on the right- 

 hand, cut into two ; carino-lateral and lateral compart- 

 ments to the left-hand ; 5 c, tergum, internal view. 



