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some of their distal hairs were long (about the same as in fig. 6 of Ph. (Pli.) Lilljeborgi) ; the
most posterior-ventral bristles in this row are, however, sometimes almost completely smooth.
Inside the inner edge of the rostral incisur, somewhat posteriorly, there is a short, simple bristle.
Apart from these the rostrum and the part round the incisur are quite without bristles. A short
distance behind the incisur on a rather short part of the list there is a somewhat varying number
(about ten to twenty) of moderately long and finely feathered bristles; apart from these the list
is almost entirely without bristles along the ventral margin of the shell; inside the posterior
margin of the shell it has a moderate number of rather short, smooth, fine bristles. Along the
ventral margin of the shell the list is narrow, posteriorly it is somewhat wider. The selvage
is almost exactly similar in all the species of this genus that have been investigated by me.
It is well developed both on the rostrum and along the whole ventral side of the shell; on the
rostrum and along the edges of the incisur it is very wide (the incisur is quite filled by it), but
it is also rather wide along the whole ventral margin of the shell. On the rostrum and along
the edges of the incisur it is divided by a coarse striation into narrow rectangular portions;
this coarse striation gradually comes to an end, however, behind the incisur; along its whole
length the selvage is also finely cross-striated; this cross-striation is, however, sometimes rather
difficult to verify with certainty at certain parts. On the rostrum the selvage lias at the edge
rather fine hairs (cf. fig. 4 of Ph. (Ph.) Lilljeborgi) which vary in length; on the part along the
posterior edge of the incisur and just behind the incisur there are, in addition to such short hairs,
rather long marginal hairs as well, and, besides, issuing at about half the breadth of the selvage,
there are often a number of comparatively long bristles. Along the ventral margin of the shell
the selvage is also divided at the edge into short, fine hairs of different lengths; on the posterior
part they are somewhat shorter and more equal in length than they are anteriorly (see fig. 3
of Ph. (Ph.) Lilljeborgi). (In the specimens of Ph. ( Scier oconcha) Appellô ji I have had an
opportunity of investigating the selvage was very much worn, so that ail the details given here
— reproduced for Ph. ( Ph.) Lilljeborgi — could not be verified with absolute certainty for them.)
Inside the list a part of the inner lamella of the shell just behind the rostral incisur is characterized
by about nine to twelve striae, situated close together and running parallel to the margin of the
shell (see fig. 2 of Ph. (Ph.) Lilljeborgi). With strong calcareous incrustation. The forms
are rather large or of moderate size.
Male: — This differs from that of the female especially by being considerably more
elongated and by having the rostral incisur considerably more shallow and wider. The two
sexes also seem to differ a good deal in length. The male shell is less stronglv calcified. ln those
cases in which a strongly marked sculpture is present it is less developed in this sex.
First antenna: — This has strong sexual dimorphism.
Female: — This is relatively short and has six joints. The original fifth joint is
not developed; whether, as G. W. MÜLLER states, 1894, p. 23. the fourth joint has arisen by the
uniting of the original fourth and fifth joints seems to be very difficult to decide with certainty
at present; judging from the situation of the bristles the original fifth joint seems, at any rate
in this genus, to be very much reduced and it does not seem impossible that it has been eliminated,
at least in some forms, an assumption that seems to be supported by a comparison with the
Zoolog, bidrag, Uppsala. 9uppl.-Bd. T. 1 ^
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