The Isopods of Abyssal Depths in the Atlantic Ocean

158
ROBERT J. MENZIES
Figure 46. Ilyarachna nodifronoides, n. sp. A: third pleopod; B: mandible female allotype;
G: uropod female allotype; D: first antenna; E: first pleopod; F: dorsal view male holotype;
G: second male pleopod.
Measurements: Adult female length about 3 mm.
(Sars, 1897).
Type locality: Skager Rak, Norway (?).
Distribution: Subarctic and Arctic seas, and North
Atlantic, panarctic boreal, eurybathic (Hult, op. cit.,
p. 100). It was taken by the Ingolf from 14 stations
(Hansen, 1916, p. 124) and by the Thor from four
stations (Hansen, op. cit.). One Ingolf station was
abyssal: Station 113, latitude 69° 31' N., longitude
7°06'W., 2465 meters, temperature —1.0° C., one
specimen. The species was not captured by the Vema.
Ilyarachna derjugini Gurjanova
Figure 45 I
Synonyms: Ilyarachna derjugini Gurjanova, 1946a,
pp. 275-276, 294, Fig. 6.
Diagnosis: Ilyarachna with uropodal structure unknown.
Cephalon and peraeon devoid of dorsal
spines. Apexofpleon pointed. Coxal plates of second
peraeonal somite strongly recurved and pointed. Pleon
with one somite (otherwise as in hirticeps). (After
Gurjanova, op. cit.)
Measurements: Length 4 mm.
Type locality: Arctic Ocean, Sedov Station 100,
1938, latitude 81° 10' N., longitude 137° 17' E., 2500
meters (Gurjanova, op. cit. p. 293).
Distribution: Known only from type locality.
Affinities: Closely related to and possibly identical
with /. longicornis G. O. Sars, as judged from Gurjanova's
illustration and the statements by Hult, 1941,
p. 97.
Ilyarachna nodifronoides, new species
Figure 46
Synonyms: None.
Diagnosis: Ilyarachna with two pleonal somites.
Cephalon and peraeon without dorsal spines. Uropod