- Coronula diadema.
- C. testudinaria.
- C. balænaris.
- C. pulchra.
- C. denticulata.*
3. Genus Balanus. Pl. [V].
Animal. Body sessile, inclosed in an operculated shell; branchiæ numerous, placed in two rows, unequal, articulated, ciliated; each composed of two cirri, supported by a peduncle, and exsertile; mouth with four transverse dentated jaws, with four hairy palpi-like appendages.
Shell. Formed of six distinct coronary valves, one dorsal, one ventral, and two pairs of laterals, with a calcareous support; operculum forming a sort of pyramid, by four articulated pieces in the aperture of the shell. Is found in almost all seas. Thirty species.
- Balanus angulosus.
- B. nigrescens.
- B. roseus.
- B. amphimorphus.
- B. crispatus.
- B. stalaciferus.
- B. patellaris.
- B. calycularis.
- B. subimbricatus.
- B. palmatus.
- B. dupluconus.
- B. semiplicatus.
- B. lævis.
- B. punctatus.
- B. perforatus.
- B. rugosus.
- B. latus.
- B. plicatus.
- B. galeatus.
- B. spinosus.
- B. placianus.
- B. sulcatus.
- B. cylindraceus.
- B. ovularis.
- B. radiatus.
- B. fistulosus.
- B. Lyonsii.
- · · · · ·
- B. tintinabulus.*
- B. miser.*
- B. geniculatus.*
4. Genus Acasta. Pl. [V].
Animal. Body without a peduncle, and inclosed in a multivalve shell, found in sponge or marine bodies, mouth and tentacula placed in the apex, or upper part of the body.
Shell. Patella-shaped, sub-conically oval, formed of six lateral unequal valves forming the base, which being convex prevents the shell from standing by itself in an erect position, when detached from the substance which envelopes it. Inhabits the British seas. Four species.
- Acasta Montaguii.
- A. sulcata.
- A. glans.
- A. tubulosa.