- Fig. 1 a and 1 b, Balanus spongicola, external views of scutum and tergum; 1 c, var. of the tergum, from a specimen from the Cape of Good Hope; 1 d, var. of the tergum from the West Indies.
- 2, Balanus lævis.
- 2 a,””fossil, elongated var., showing lower part of basal cup filled up with a cancellated mass.
- 2 b and 2 c,””scutum, external and internal view of.
- 2 d and 2 e,””scutum (variety), internal and external view of.
- 2 f,””scutum (variety), external view.
- 2 g,””tergum, external view.
- 3 a, Balanus perforatus, scutum, internal view; 3 b, tergum, internal view; 3 c, tergum, var. external view.
- 4 a, Balanus concavus (var. from Panama), scutum, internal view; 4 b, scutum, external view; 4 c, tergum, external view; 4 d, tergum, fossil, Coralline Crag; 4 e, tergum, fossil, Italy.