The Isopods of Abyssal Depths in the Atlantic Ocean

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ROBERT J. MENZIES
Figure 31. A-C: Nannoniscus inermis Hansen. A: anterior left part of head with antennula
and antenna of female; B: outline of anterior of head of female; C: abdomen and two
posterior thoracic segments of female. D-E: Nannoniscus armatus Hansen. D: dorsal view
female; E: dorsal view head of female. F-H: Nannoniscus analis Hansen. F: abdomen of
male; G: dorsal view of male anterior; H: dorsal view of female. I-K: Nannoniscus oblongus
G. O. Sars. I: ventral view of uropods, anus, and abdomen of female; J: dorsal view of
female; K: ventral view of uropods, anus, and abdomen of male.
lateral margins distinguishes this species from the
others.
Nannoniscus oblongus G. O. Sars
Figure 31 I-K
Synonyms: Nannoniscus oblongus G. O. Sars, 1870,
p. 164; —1897, p. 119, PI. 50 (female only); —
Hansen, 1916, pp. 92-94, PL VIII.
Diagnosis: Nannoniscus with cephalon as much as
seven times as broad as the distance between the
anterior ends of the cephalic keels. Antero-lateral
angles with stiff spine or seta on first, second, and
third somites. Operculum with a large medial spine
and with distal margin semi-circular. Uropodal exopod
shorter than endopod. Pleon without teeth.
Measurements: Largest male 2.2 mm. (Hansen,
op. cit.).
Type locality: Off the Lofoten Islands, at Skraaven,
in depths ranging from 225 to 468 meters (Hansen,
op. cit.).
Distribution: North Atlantic: Davis Strait, Ingolf
Station 32, latitude 66° 35' N., longitude 56° 38' W.,
599 meters, temperature 3.9° C.; west of Iceland,
Ingolf Station 98, latitude 65° 38' N., longitude 26°
27' W., 260 meters, temperature 5.9° C.; southwest
of Iceland, Ingolf Station 78, latitude 60° 37' N.,