download pdf

115
best recognized hy the absolute want of lateral spines, and the . pale colour of
the body.
Occurrence. Though nowhere in any abundance,
I have met with this
form in several places on the west coast of Norway, and always in rather con-
siderable depths, ranging from 60 to 150 fathoms.
Distribution. British Isles (Kobertson), Kattegat (Meinert).
3. Pleurogonium spinosissimum, G. 0. Sars.
(PI. xLvm, fig. y.)
Plewacantlia spinosissima, G. 0. Sars, Beretning oni en i Soinmeren 1865 fovetagen zool. Keise
ved Kysterne af Christianias og Christiansands Stifter, p. 30.
Specific Characters. Body oblong oval in form, slightly tapering posteriorly.
Cephalon blunted in front, and slightly eniarginated
on each side at the insertion
of the superior antennce. Lateral parts of the 4 anterior segments
of mesosome
irregularly angular, and each projecting into 2 diverging serrated processes, the
anterior of which more properly represents the produced coxal plate of the cor-
responding segment. The 3 posterior segments of mesosome, as usual, much
smaller than the anterior, and each having laterally a single strong, serrated
spine, likewise representing the produced coxal plate. Caudal segment rather
large, obcordate, lateral edges considerably bulging in the middle and densely
hairy in their outer part, tip acutely produced. The several appendages
of the
body resembling in structure those in the 2 preceding species, excepting that the
female operculum is comparatively much broader and very acutely produced at
the tip. Colour bright red. Length
of adult female 3 mm.
Remarks. This is a very distinct species, easily recognizable from the
other known forms by the coarse armature of the body, which, indeed, has given
rise to the specific name. It is also of considerably larger size.
Occurrence. I have found this pretty species occasionally in several lo-
calities of the Norwegian coast, from the Christiania Fjord to Yardo, in depths
ranging
from 50 to 100 fathoms.
Distribution. British Isles (Robertson), Kattegat (Meinert).