confinement. The eggs of Squilla, like those removed from the body of
the Crab, die because they are deprived of the rapid stream of fresh
water which the mother drives through her hole for the purpose of her
own respiration.

The accompanying representation of the embryo of Squilla shows that it
possesses a long, segmented abdomen without appendages, a bilobate tail,
six pairs of limbs, and a short heart; the latter only pulsates weakly
and slowly. If it acquires more limbs before exclusion, the youngest
larva must stand on the same level as the youngest larva of Euphausia
observed by Claus.

(FIGURE 34. Embryo of a Squilla, magnified 45 diam. a. heart.

FIGURE 35. Older larva (Zoea) of a Stomapod, magnified 15 diam.)

Of the two larval forms at present known which are with certainty to be
ascribed, if not to Squilla, at least to a Stomapod, I pass over the
younger one* (* 'Archiv fur Naturgeschichte' 1863 Taf 1.) as its limbs
cannot be positively interpreted, and will only mention that in it the
last three abdominal segments are still destitute of appendages. The
older larva (Figure 35), which resembles the mature Squilla especially
in the structure of the great raptorial feet and of the preceding pair,
still wants the six pairs of feet following the raptorial feet. The
corresponding body-segments are already well developed, an unpaired eye
is still present, the anterior antennae are already biramose, whilst the
flagellum is wanting in the posterior, and the mandibles are destitute
of palpi; the four anterior abdominal segments bear biramose natatory
feet, without branchiae; the fifth abdominal segment has no appendages,
and this is also the case with the tail, which still appears as a simple