[5.] [Pollicipes sertus], one and a half nat. size.

[TAB. VIII.]

Fig.

[1.] A piece of rock bored in two directions by [Lithotrya dorsalis], with the calcareous basal discs in the upper cavity, serving as a bridge for crossing an old cavity. About twice natural size.

[1a´.] [Lithotrya dorsalis], (nearly twice nat. size), with the basal calcareous cup adherent; (a), rostrum on same scale, seen externally.

[1b´.] [Lithotrya dorsalis], rostrum and the rostral corners of the two scuta, together with a small portion of the subjacent membrane of the peduncle, with its calcareous scales; viewed externally, greatly magnified, showing the inferior crenated edges of the scales.

[1c´.] [Lithotrya dorsalis], basal calcareous cup, one and a half the natural size; this is the largest specimen which I have seen.

[2.] [Lithotrya nicobarica], (magnified nearly twice;) attached to the rock, copied from Reinhardt; (a), rostrum on the same scale, with the other valves, seen externally; (b), section of the row of discs; (c), extreme point of the peduncle, extending beneath the row of discs.

[2a´.] Rock bored by [Lithotrya nicobarica], showing the row of calcareous discs, copied from Reinhardt.

[3.] [Lithotrya cauta], magnified between seven and eight times; (a), scutum; (b), tergum.