FIGURES 22 AND 23 of unknown origin.)

It is further to be remarked that the Zoeae of the Crabs, as also of the
Porcellanae, of the Tatuira and of the Shrimps and Prawns, are
enveloped, on escaping from the egg, by a membrane veiling the spinous
processes of the carapace, the setae of the feet, and the antennae, and
that they cast this in a few hours. In Achaeus I have observed that the
tail of this earliest larval skin resembles that of the larvae of
Shrimps and Prawns, and the same appears to be the case in Maia (see
Bell, 'Brit. Stalk-eyed Crust.' page 44).

Widely as they seem to differ from them at the first glance, the Zoeae
of the Porcellanae (Figure 24) approach those of the true Crabs very
closely. The antennae, organs of the mouth, and natatory feet, exhibit
the same structure. But the tail bears FIVE pairs of setae, and the
dorsal spine is wanting, whilst, on the contrary, the frontal process
and the lateral spines are of extraordinary length, and directed
straight forward and backward.

(FIGURE 24. Zoea of Porcellana stellicola, F. Mull. Magnified 15 diam.

FIGURE 25. Zoea of the Tatuira (Hippa emerita), magnified 45 diam.

FIGURE 26. Zoea of a small Hermit Crab, magnified 45 diam.)

The Zoea of the Tatuira (Figure 25) also appears to differ but little
from those of the true Crabs, which it likewise resembles in its mode of
locomotion. The carapace possesses only a short, broad frontal process;
the posterior margin of the tail is edged with numerous short setae.