mber of
the segments, especially the lower ones, have very obscure
articulations, to be seen only with a high power, and these can be
capable of little or no movement.

_First Cirrus_ placed far from the second, with the top of its pedicel
on a level with the top of the lower segment of the pedicel of the
second cirrus; rami short, barely half the length of those of the second
cirrus; unequal, the anterior ramus being only two thirds of the length
of the posterior one; the shorter ramus contains thirteen
inverted-conical segments, with one side rather protuberant; the longer
ramus contains twenty-three thinner segments; the segments on both rami
are clothed with bristles, arranged in two or three rows, forming narrow
transverse brushes.

_Second Cirrus_, with its pedicel long, and its rami nearly equalling in
length those of the sixth pair; the two rami of nearly equal length; the
anterior one rather thicker than the posterior one; this posterior ramus
has fifty-five segments! The bristles on the second and third cirri are
arranged on the same principle as on the three posterior pair; but from
an increase in size and number of the little intermediate bristles
between the main pairs, and of those on the lateral rims, the segments,
especially the basal ones, of the anterior ramus of the second cirrus,
are clothed with thin brushes of bristles; these same bristles, on the
posterior ramus of the second, and on both rami of the third cirrus, can
hardly be said to form brushes, though longer and more numerous than
those on the three posterior pair of cirri.

_Fifth and Sixth Cirri._--These resemble each other, and have their
inner or posterior rami in an almost rudimentary condition. In the sixth
cirrus (Pl. X, fig. 28) the outer ramus (_a_) has actually sixty-three
segments, whereas the rudimentary ramus (_k_) has only eleven, nearly
cylindrical segments. These are furnished with extremely minute spines,
of which those on the dorsal face are longer than those on the anterior
face; the spines on the summit of the terminal segment are the longest;
the segments are not half as thick as the normal ones in the outer
ramus. The rudimentary ramus is only one seventh part longer than the
pedicel which supports both it and the normal ramus. In the fifth
cirrus, the rudimentary ramus is rather longer, and has thirteen
segments, resembling those in the rudimentary ramus of the sixth. In the
fourth cirrus there is no trace of this pe