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133
Expedition, and are recorded by Mr. Fr. Beddard as M. gracihs,
austmlis and
latift'ons; the 4th is described by Dr. Hansen as M. longicornis, from a specimen
procured during the German Plankton-Expedition. It is, however, somewhat
questionable, if all these species are actually referable to the present genus. Thus,
in the species described by Dr. Hansen, the structure of the mandibles is very
different from that in Munnopsis typica; and the Challenger species, to judge
from the not very exhaustive description given by Mr. Fr. Beddard, seem also
to differ very materially in several respects from the type species.
Munnopsis typica,
(PL LVII & LVIII.)
M. Sars.
Munnopsis typica, M. Sars, Chr. Vid. Selsk. Porliandl. I860, p. 84.
Specific Characters. Anterior division of body in female very broad,
rounded in outline, in male somewhat narrower, oval; posterior division very much
narrower and longer than the anterior. Cephalon deeply sunk within the 1st segment
of mesosome, and provided with 2 juxtaposed tubercles above at the base, frontal
part narrowly produced between the bases of the superior antennse, and transversely
truncated at the tip. The 4 anterior segments of mesosome separated above by
smooth, thin-skinned interspaces, and distinctly excavated trans ver sally,
the anterior and posterior edges somewhat elevated, lateral parts
with both
each with a
transversely oval eminence above, those of the 2 posterior segments larger than
those of the 2 anterior; coxal plates distinct, though very small. The 3 poste-
rior segments of mesosome combined scarcely more than half as long as the an-
terior division of the body, and defined by very oblique, arched sutures, the last
2 each having 2 juxtaposed tubercles dorsally, lateral parts narrow, and extended
obliquely behind. Caudal segment considerably exceeding in length the 3 preced-
ing segments combined, and of narrow oblong oval form, with a single small
tubercle above at the base, tip bluntly produced, lateral edges gently curved and
perfectly smooth. Superior antenna1 with the basal joint triangular in outline,
inner corner considerably produced, flagellum very slender and composed of
numerous short articulations carrying delicate sensory filaments. Inferior antennae
more than 4 times as long as the body, flagellum shorter than the peduncle. 1 st
pair of legs of same appearance in the two sexes, carpus slightly
curved and
exceeding the propodos in length, dactylus short; 2nd pair considerably stronger in
male than in female, with the carpal joint slightly tumefied and densely armed
with short spines inside, dactylus elongated. The 2 succeeding pairs of legs fully
3 times as long as the body, and terminating in a slender claw. Natatory legs