Notodelphys tenera Thorell, 1859

(Fig. 19)

Material examined. 1 ♀, 3 ♂♂ (MNHN-IU-2018- 1772) from Ascidia obliqua Alder, 1863, middle of fjord, Kristineberg, Sweden; 1 ♀ (dissected and figured) from A. obliqua, Norway, Norbi Stn CP11, depth 300 m.

Diagnostic characters of female. Body (Fig. 19A) of dissected specimen 3.0 mm long. Caudal ramus (Fig. 19B) rectangular, about 3.6 times longer than wide (193×53 μm) and 1.4 timeslongerthan anal somite, setulose along outer margin; outer lateral seta positioned at 75% of ramus length.

Rostrum (Fig. 19C) tapering, about 1.5 times as long as wide, minutely bifurcate at apex. Antennule 15- segmented. Antenna (Fig. 19D) with 2 equally large setae on basis representing exopod; compound distal endopodal segment slender, about 5 times as long as wide; terminal claw small, about 1/3 aslongas segment.

Mandible (Fig. 19E) with patch of fine spinules proximally on outer surface of basis; endopod armed with 3 and 9 setae on first and second segments, respectively. Maxillule (Fig. 19F) with 10 setae on precoxal arthrite; endopod distinctly 2-segmented with 1 and 4 setae on first and second segments, respectively; 3 of distal setae on second endopodal segment naked. Maxilla (Fig. 19G) 5- segmented; syncoxalarmature elements 4, 1, 2, and 3 setae on first to fourth endites, basis with claw plus 2 setae, and with 1, 1, and 3 setae on first to third endopodal segments. Maxilliped (Fig. 19H) 3-segmented and armedwith 10, 1, and 3 setae on first to third segments, respectively.

Leg 1 basis with short inner distal spine less than half as long as first endopodal segment; exopod distinctly shorter than endopod; first exopodal segment with several spinules on outer margin; first endopodal segment about 1.6 times longerthan wide. Spines on outer margin of exopods of legs 2–4 slender, smooth, and straight.

Leg 5 (Fig. 19I) protopod distinctly articulated from ventral surface of pedigerous somite, ornamented with 4 or 5 spinules on inner distal margin, outer distal process slightly shorter than exopod and tipped with pinnate seta; free exopodal segment bulbous, narrowed proximally, about 1.7 times longerthan wide (61×37 μm), with convex outer margin and almost straight inner margin bearing 6 or 7 spinules; distal armature comprising inner spine and outer seta about as long as segment

Remarks. The characteristic shape of the free exopodal segment of leg 5 in the female allows this species to be easily identified. This species has a distribution ranging from Scandinavia in the North to the Mediterranean (Illg, 1958).