On the inner branches the chelae
are developed; the outer branches are lost before an inner branch has
made its appearance on the fourth segment (Figure 32). The latter again
becomes destitute of appendages, so that in this case at an early period
four, and at a later only three, segments of the middle-body bear limbs.
The fifth segment is still entirely wanting, whilst all the abdominal
segments have also acquired limbs, and this one after the other, from
before backwards. The adult animal, as shown by the three pairs of
chelae, will certainly be very nearly allied to the preceding species.*
(* The oldest observed larvae (see Figure 33) are characterised by the
extraordinary length of the flagella of the outer antennae, and in this
respect resemble the larva of Sergestes found by Claus near Messina
(Zeitschr. fur Wiss. Zool. Bd. 13 Taf 27 Figure 14). This unusual length
of the antennae leads to the supposition that they belong to our
commonest Prawn, which is very frequently eaten, and is most nearly
allied to Peneus setiferus of Florida. Claus's Acanthosoma (l.c. Figure
13) is like the younger Mysis-form of the larva figured by me in the
'Archiv fur Naturgeschichte,' 1836, Taf 2, Figure 18, and which I am
inclined to refer to Sicyonia carinata.)
The youngest larva of the Schizopod genus Euphausia observed by Claus,
stands very near the youngest Zoea of our Prawns; but whilst its
anterior antennae are already biramose, and it therefore appears to be
more advanced, it still wants the middle maxillipedes.
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