3. [BALANUS] PSITTACUS. Pl. [2], fig. [3 a]-[3 d].
LEPAS PSITTACUS. Molina. Hist. Nat. Chile (1788), vol. i, p. 223.
BALANUS PICOS. Lesson. Zoolog. Voyage de la Coquille (1829).
------ TINTINNABULUM (var. c). Ranzani. Mem. di Storia Nat. tab. 3, fig. 1-3 (1820).
------ CYLINDRACEUS. Lamarck, in Chenu. Illust. Conch. Tab. 4, fig. 17, Tab. 5, fig. 7, sed non var. (c.) in Lamarck, Animaux sans Vert., (1818).
------ PSITTACUS. King and Broderip. Zoolog. Journal, vol. v (1832-1834), p. 332.
Shell, pale dirty pink; orifice hexagonal. Scutum with the articular ridge very small, confluent with the very prominent adductor ridge, forming a tubular cavity, which extends up to the apex of the valve. Tergum with the apex produced, needle-like, purple: spur placed at less than its own width from the basi-scutal angle.
Hab.—Peru, Chile, Chiloe, Patagonia. Fossil in an ancient tertiary deposit, Coquimbo; and in a superficial, recent bed at S. Josef, in Patagonia.
General appearance.—Shell either almost cylindrical or steeply conical, generally flesh-coloured, sometimes pale pink; surface either smooth (when not disintegrated) or sometimes with the parietes distinctly and rather strongly ribbed, with the ribs distant from each other: I have seen six or seven ribs on the rostrum alone. The orifice in the most perfect specimens is nearly equilateral and hexagonal. The radii generally are very broad, but occasionally quite narrow, and even linear. The basis is generally deeply and irregularly cup-formed.