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twelve. Among these twelve species therc are several of which a fairly abundant material
was at the disposai of the investigator, e. g. C. spinifera and C. elegans. This faet alone should
have aroused the author’s suspicion.
With regard to the eight former species 1 may point out the following facts:
C. zetesios: — Only two stages, „Stage (?) I" and „Stage (?) II“ of this species, which
G. H. FOWLER himself established in the work in question, were found in the material
investig-ated by this writer and only females were found of both. The same stages were also found
by me in material brought home by the „M i c h a e 1 S a r s“ from the deep sea expedition
of 1910. Both males and females were found. As I hope to be able to show in a subséquent
work on the Ostiacods of this expedition, these two stages represent in all probabilitv
the first and the second larval stages of C. macrocheira G. W. MÜLLER.* Because of this G. H.
FOWLER’s assumption that the last-mentioned species is „Stage I“ of C. magna C. Cl. AI s
also collapses.
C. rotundata: — As is pointed out below (in a note on C. rotundata), it seems to me extremei v
probable that this species, as it is at present taken in the literature, is not a unit; it probable
consists of two forms very closely related to each other, one of which has a somewhat more
elongated shell than the other. This view is supported by the faet, among others, that the
geographical distribution of these two forms does not seem to be the same; while both forms
are found, for instance, in the Bay of Biscay and in the greater part of the Atlantic, only the
more elongated form seems, on the other hånd, to occur in the Antarctic. According to G. H.
FOWLER’s presentation the larvae of this species always belong to the short and high type.
According to what I have observed myself the larvae of the elongated Antarctic form have
about the same elongated type as the mature individuals. Elongated larvae are thus found.
It does not seem to me impossible that these also occurred in the material investigated by
G. H. Fowler but were overlooked on account of their small number; one ought to note the
great difference in number between elongated and short mature specimens in this material
the latter were very numerous, the former, on the other hånd, very sparse. Finally it is to
be noted that G. H. FOWLER did not succeed in „bringing out clearlv the successive stages“
in the measurements taken by him to prove Brooks’s law in this species. This faet too
seems to indicate that the material was not pure from a systematic point of view.
C. spinirostris: — In the case of this species too it seems to me probable that a confusion
has taken place between two very closely related forms. For the reasons in support of this
view of mine I shall in this connection only refer to what I have written below, remarks on
C. spinirostris.
C. Haddoni: — In the material investigated by G. H. Fowler only two mature males
of this species were found, both with shells 2,1 mm. long, and three male larvae, all with shells
* As can be seen from the following words G. H. Fowler himself had a presentiment of the close relalionship
between „C. zetesios“ and C. macrocheira; he weites p. 251 : „The species obviously belongs lo the magna group.
While the shell-contour to some extent resembles that of ..macrocheira“, ils frontal organ and the slender longer bristle
of the inner joint of antenna 11. are very far from the magna-macrochcira type; nor can it be fitted into the lenglhs
which have been worked out for that series. Il is remotely possible that it may be a dimorphic parthenogenetic
form of magna, but parthenogenesis has not yct been shown to occur in the Ilalocypridae“.
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