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7 7/ e homologi z a t ion
oj ihr distal hrist 1rs
of the first antenna.
bristle is also to be found on the male first antenna. This bristle is situated near the distal bristles
in the female, because of the smallness of the end joint, but in the male it is rather far removed
from these bristles. It is certain that we are not concerned liere with a displacement of this
bristle, as in the male, just as in the female, it is situated distally on the sixth joint; on the
contrary its removal from the other bristles is due to the strong development of the end joint.
If G. O. SARS’s assumption that the original fémale sixth joint had been split were correct, it
is clear that this bristle ought still to be situated close to the end bristles; in order to reach its
present place it must have shifted right across the joint that G. O. Sars describes as the seventh,
a phenomenon that seems anything but probable.
Nor is the small part that G. O. Sars denoted as the end joint homologous with the part
that I showed above ought perhaps to be distinguished as a special, an eighth, joint. Accorcling
to G. O. Sars the former part carries the b-, c-, f- and g-bristles. The latter part, on the other
hand, has the (cl-), e-, f- and g-bristles. The latter part is moved in the male by two verv strong
muscles, fixed proximally at about the boundary between the sixth and seventh joints.
These muscles have no homologon in the females of this genus. On the other hand the eighth
joint of the first, antenna of all the species belonging to the sub-family Cypridininae that I had
an opportunity of investigating closely is moved by two muscles which are certainly homologous
with these. In this sub-family as well these muscles arise on the boundary between the sixth
and seventh joints, but, on account of the comparatively smaller size of the seventh joint they
are not inconsiderably smaller.
It follows from this that G. W. Müller’s idea of the male end joint, quoted above, is
also incorrect. — Nor can this author’s statement that the fifth and sixth joints of the male
first antenna are always united be correct eit-her, as is shown by the genus description I have
given above; for all the species investigated by me had these joints free. But it does not seem
impossible, however, that in some species of this genus these two joints are joined into one.
This view is supported first by the faet that the boundary between these joints is sometimes,
at least partly, rather weakly developed, secondly that the sixth joint is not moved by any
special muscles. It is, however, to be noted that G. W. Müller’s own figures, both those in
his large monograph of 1894 and others as well, directly contradict his statement. I shall
only point out here that in pi. 4, figs. 15 and 17, of the mentioned work the boundary between
these two joints is very well drawn, although on the former the boundary between the fourth
and the fifth and on the latter the boundaries between both the fourth and the fifth joints on
the one hånd and the sixth, seventh and eighth joints on the other are not drawn. As far
as this writer’s statement, 1894, p. 23 that the fourth and the fifth joints are always joined
in the male first antenna is concerned, this seems to be exceedingly prob lema tical. In the
first place I have always found these two joints well divicled from each other on the species
investigated by me, and secondly the fifth joint is moved by no less than three special muscles.
From what. has been said above it also follows that G. S. BRADY’s and A. M. NORMAN’s
information, 1896, is not cpiite correct.
A number of facts show the correctness of the homologization of the various distal bristles
on the first antenna of the male and the female which has been adopted above. It may of course
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