ttle valves, as I believe,
represent the scuta and terga, though they are placed considerably below
the orifice: the little bristly points have no homological
signification, and are absent in the male of the following closely
allied species. The four pairs of limbs answer to the four posterior
cirri, as may be inferred from their proximity to the abdominal lobe,
and from the three posterior pairs closely resembling each other, and
differing a little from the first pair; this latter pair corresponds
with the third pair in the hermaphrodite form of Scalpellum. If I am
right in believing that only a single vesicula seminalis is ordinarily
developed in the male, this is a special and singular character.

As stated in the beginning of this description, from the one great fact
of the absolute correspondence of the prehensile antennae of the
parasite, with those of the hermaphrodite _Scalpellum vulgare_, together
with its fixed condition, its short existence, and exclusively male sex,
I have thought myself justified in provisionally considering it as the
Complemental Male of the Cirripede to which it is attached; but I hope
final judgment will not be passed on this view, until the whole case is
summed up at the end of the genus.[54]

[54] I trust, before long, that some naturalist, with more skill
than I possess, will examine these parasites on _Scalpellum
vulgare_, which unfortunately is the only species of the genus
that can be easily obtained. Fresh specimens, or those preserved
in spirits of wine, are necessary. The action of boiling caustic
potash is very useful in cleaning the prehensile antennae. If
these latter organs are sought in the hermaphrodite for the sake
of comparison, young specimens, adhering to clean branches of a
coralline, should be procured, and caustic potash used.

2. SCALPELLUM ORNATUM. Pl. VI, fig 1.

THALIELLA ORNATA. _J. E. Gray._ Proc. Zoolog. Soc., 1848, p. 44,
Annulosa, Plate.

_S. (Foem.) valvis 14, sub-rufis: lateribus superioribus
quadranti-formibus, arcu crena profunda notato._

(Fem.) Capitulum with 14 reddish valves: upper latera quadrant-shaped,
with the arched side deeply notched.

Mandibles with three teeth; maxillae narrow, bearing only four or five
pair of spines.

MALES, two, lodged in cavities on the under sides of the scuta;
pouch-formed, with four unequal, rudimentary valves: no mouth: cirri not
prehensile.

Algoa Bay, South Af