216 
us the future lines of study with the cirriped systematics. In the 
following report I, therefore, mainly follow the lines drawn up by 
Pilsbry, although with some alterations as to the pedunculated 
forms. These alterations are mainly based upon studies of devel- 
opment series, and on phenomena of growth, which alford a good 
base for phylogenetic deductions. An introductory chapter more 
specially deals with the results of these studies. 
The biological station of the Kristiania university, 
26th May 1921. 
(With exception of (fig. 2, a —c, fig. 6, a—c, fig. 15, a—c, flg. 17, a — 
fig. 20 a, fig. 21, a—b, fig. 44, a—d, fig. 47, and fig. 66 a all figures have been 
drawn by aid of an Abbé’s projecting apparatus at a somewhat larger scale, 
and then reduced during reproduction so that the enlargements indicated 
have been arrived at.) 
Lepadomorpha Pilsbry, 
their phylogeny and system. 
The offspring of the cirripeds is like their relations to other 
crustaceans, wrapped in darkness, and although the pupa-stage oc- 
curs with an astonishing uniformity in the whole of the group, it 
does not give any hold for a judgment as to the origin of the 
cirripeds. If we study the literature, we moreover find opinions 
to be rather diverging as to which genus of the recent cirripeds 
is the most primitive. 
Darwin in his classic monograph (1852), does not give any 
detailed discussion of the phylogeny; nevertheless we can deduce 
from his remarks that he looked at Oxynaspis, or the type repre¬ 
sented by this genus, as the most primitive cirriped, and that he 
thought that the other genera have originated from the named 
form. Just the opposite opinion was set forth by Hoek (1883); 
he considers Mitella ( Pollicipes) as the ancestor of all recent cirri¬ 
peds, and thus comes to the result that all other genera have 
arisen through a reductive development, as regards the skeleton- 
