_Nainereis hespera_ sp. nov.
This is apparently a smaller species than _longa_ or _robusta_ and is
composed of fewer segments. It differs from those species in having the
anterior division of the body composed of only nineteen segments and
in having the first branchiæ appear on the thirteenth or fourteenth
segment. The prostomium is broadly subtrapeziform, narrowing forward
and with the anterior margin varying from slightly convex to mesally
indented as is the case in the type; dorsal surface nearly flat, simply
marked with two furrows, or sometimes with the median caudal region
between furrows elevated. Peristomium with anterior margin above more
or less concave, its median length about equal to that of the second
segment, which is also ordinarily bowed caudad. In the neuropodia
of the anterior region the postsetal processes are broad, distally
rounded, thick lips which are prominent; in the posterior region these
become narrowly conical, elongate, distally pointed processes. The
postsetal processes of the notopodia in the anterior region are thick,
short cones which increase in length in going caudad, in the posterior
region being very elongate. The branchiæ begin on the thirteenth or
fourteenth segment as short processes but become abruptly longer,
basally thick and distally pointed processes much thicker than the
postsetal processes of the notopodia and exceeding these in length;
they are widely separated and, while curving in somewhat mesad, do
not come in contact, leaving much of the middorsal region naked. They
continue to the end of the body. The neuropodial setæ of the anterior
region are arranged in three subvertical series and form a patch twice
as high (dorsoventrally) as long (cephalocaudally). The stout setæ
of the posterior row are mostly four in number, less commonly three
or five. These coarse setæ are not at all clavate as in elongata and
are not roughened or cross-ridged above the curve as in robusta; the
terminal region above the curve longer than in the later species.
The setæ of the other series are more curved than in robusta and are
abruptly contracted farther from the body, the contraction stronger
but the one edge similarly roughened or denticlated with cross lines.
At the ventral end of the series a small patch of ordinary, camerated,
capillary setæ resembling the notopodials. The body is broad anteriotly
and narrows to the posterior end. Dorsal surface flat and the ventral
convex as usual. Number of segments in the type one hundred and
thirty-six. Color in general pale brown; at black spot at base of each
branchia at least those of posterior region, in front and behind and
the proximal part of branchia often darkened.
Length, 27 mm.; greatest width, 2.4 mm.
Type--M. C. Z. 2, 161.
_Scoloplos acmeceps_ sp. nov.
Resembling _S. armiger_ (O. F. Müller) in general structure. A less
deeply pigmented species easily distinguished from this northern
form in wholly lacking the ventral papillæ (neurocirri) present in
the latter below the parapodia of about the eighteenth to thirtieth
segments. The prostomium is similarly elongate and pointed but is more
slender; it is borne at the end of the peristomium which has the form
of a truncate cone. The branchiæ begin anteriorly in the same way as
very slight elevations and increase quickly to long ligulate forms;
but the first one appears on the sixteenth or seventeenth setigerous
segment instead of on the twelfth or thirteenth as usual in armiger.
The fully developed branchiæ are obviously narrower than typical for
the latter species. The lobes of the parapodia are in general similar
though they do not become obvious so far forward. In the second
division of the body the ventral lobe is similarly elongate and bifid
at the tip with the inner or more dorsal lobe the longer; but the lobes
are characteristically more divergent, thinner and more slender. The
first bifid neuropodial lobes appear on the twenty-first setigerous
segment. The dorsal lobe similar in form to that in armiger. Caudal
end of all the types missing.
Greatest width, 2 mm.
Type--M. C. Z. 2, 162.
Balboa (Sept. 10, 1917).