liver of the Crab are shown. Animal and roots deep yellow.

FIGURE 60. Young Sacculina purpurea with its roots; the animal
purple-red, the roots dark grass-green. Magnified 5 diam.)

Out of several Cirripedes, which are anomalous both in structure and
development, Cryptophialus minutus must be mentioned here; Darwin found
it in great quantities together in the shell of Concholepas peruviana on
the Chonos Islands. The egg, which is at first elliptical, soon,
according to Darwin, becomes broader at the anterior extremity, and
acquires three club-shaped horns, one at each anterior angle and one
behind; no internal parts can as yet be detected. Subsequently the
posterior horn disappears, and the adherent feet may be recognised
within the anterior ones. From this "egg-like larva"--(Darwin says of
it, "I hardly know what to call it")--the pupa is directly produced. Its
carapace is but slightly compressed laterally and hairy, as in Sacculina
purpurea; the adherent feet are of considerable size, and the natatory
feet are wanting, as, in the adult animal, are the corresponding cirri.
As I learn from Mr. Spence Bate, the Nauplius-stage appears to be
overleaped and the larvae to leave the egg in the pupa-form, in the case
of a Rhizocephalon (Peltogaster ?) found by Dr. Powell in the Mauritius.

(FIGURES 61 TO 63. Eggs of Tetraclita porosa in segmentation, magnified
90 diam. The larger of the two first-formed spheres of segmentation is
always turned towards the pointed end of the egg.

FIGURE 64. Egg of Lernaeodiscus Porcellanae, in segmentation, magnified
90 diam.)

I will conclude this general view with a few words upon the earliest