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.
The Zoea of the Hermit Crabs (Figure 26) possesses the simple inner
antennae of the Zoea of the true Crabs; the outer antennae bear upon the
outside on a short stalk a lamella of considerable size analogous to the
scale of the antennae of the Prawns; on the inside, a short, spine-like
process; and between the two the flagellum, still short, but already
furnished with two apical setae. As in the Crabs, there are only two
pairs of well-developed natatory feet (maxillipedes), but the third pair
is also present in the form of a two-jointed stump of considerable size,
although still destitute of setae.
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