218 
first develops five chitinous — in Darwin’s nomenclature „prim- 
ordial“ — valves, viz. carina, terga, and scuta. In the following 
report more instances of this are given, and, what is of import¬ 
ance in this connection, this also holds good in genera with skelet- 
ons consisting of several more plates in the adult, such as in f. 
inst. Mitella, and Scalpellum. It is curious, how little attention 
Hoek and other authors have paid to this faet which is, however, 
together with the faet that no other plates are preformed as chit- 
inal plates, of great phylogenetic importance. They prove that these 
five valves have probably been present in the group, before the 
cirripeds acquired their capacity of producing calcareous plates, 
and further, that the accessive plates of the animal probably are 
later acquisitions. 
This makes us return to the theory of Darwin, although in 
a somewhat modified form. The origin of the cirripeds is to be 
sought in a form with only five primordial, chitinal valves in the 
mantie, and without calcareous skeleron of the peduncle. 
From this point of view we shall have to modify the ideas of rela- 
tionship and also more or less the systematic arrangements set forth 
by Hoek, Gruvel, Pilsbry, and Annandale. We are forced 
to discard the theory of Mitella as being a most ancient cirriped 
with which the other genera have originated. I shall in some words, 
therefore, discuss the relationships of the peduneulate cirripeds. 
We may then, to begin with, also discard the theory of Oxy- 
naspis as the primitive genus. On the one hånd its special bio- 
logy, its symbiosis with Antipatharians contradicts this view, and 
moreover we must point out the faet that the genus is herma- 
phroditic, with no trace of a male. 
Taking the lower crustaceans as a whole, we at once see that 
hermaphroditism is by no means a common feature; on the con- 
trary, the overwhelming majority has separated sexes, and where 
hermaphroditism is present, it is evidently a secondary phenom- 
enon, an adaptation to special biological conditions. We are there¬ 
fore forced to consider the hermaphroditism of the cirripeds as a 
secondary phenomenon, an adaptation to their fixed mode of living, 
and we may take it for granted that the ancestors of the group 
had separate sexes, probably of equally high organisation. 
Kriiger in his recent paper (1920, p. 46) maintains the old 
