or quite obsolete, the short prominence, however, being noticeable. The upper margin of the larger (right) cheliped is more even than is shown in Whitelegge's figure. The chelipeds are unequal in both sexes.

This hermit-crab is somewhat peculiar in its habits; it was found by Mr. Oliver under stones between tide-marks, and he states that it was not common, and that it never uses a spiral shell, but manages to keep on its back a single valve of a bivalve mollusc's shell or a vacant Siphonaria or limpet shell.

Only three species of this peculiar genus are as yet known—viz., P. edwardsi, from Campbell Island and the Snares; the present species; and P. platei, from Juan Fernandez. The description of this latter species I have not yet been able to obtain. Mr. Whitelegge's specimens were dredged in 54–59 fathoms, off the coast of New South Wales, and the species to which they belong is much smaller than P. edwardsi, and appears to differ also in having the chelipeds unequal in the female, while in the female of P. edwardsi, according to Filhol, the chelipeds are small and subequal.