Notodelphys elegans Thorell, 1859

(Fig. 16)

Material examined. 11 ♀♀, 7 ♂♂ (MNHN-IU-2018- 1768) and 1 dissected ♀ (figured) from Ciona intestinalis (Linnaeus, 1758), Adriatic Sea.

Diagnostic characters of female. Body (Fig. 16A) of dissected female 2.50 mm long. Caudal rami (Fig. 16B) widely separated from one another, about 2.9 times longer than wide (132×45 μm) and about 1.1 timeslongerthan anal somite (118×145 μm), and setulose on both outer and inner margins; outer lateral seta located at 67% of ramus length.Rostrumlongerthanwide, taperingtowardsangular apex. Antennule 15-segmented. Antenna rather stout with 2 equal exopodal setae; compound distal endopodal segment about 3 timeslongerthan wide. Mandibular endopod with 3 and 9 setae on first and second segments, respectively. Maxillule indistinctly 2-segmented with 1 and 4 setae on first and second segments, respectively. Maxilla 5-segmented; syncoxawith 4, 1, 2, and 3 setaeon first to fourth endites, respectively; basis with claw plus 2 setae; endopod 3-segmentedwith 1, 1, and 4 setaeonfirst to third segments, respectively. Maxilliped with 10, 1, and 3 setae on first to third segments, respectively. Legs 1–4 as typical for genus. Leg 5 (Fig. 16C) protopod with about 15 spinules scattered irregularly along inner margin and with elongate outer extension bearing plumose seta at tip and 1 subdistal tooth on inner margin; exopodal segment subcircular, about 1.3 times as long as wide (32×25 μm), armedwith 1 spineand 1 plumose seta; ornamented with 1 denticle distally on outer margin and 3 spinules on inner margin near base of spine.

Remarks. As Sars (1921) noted, the caudal ramus is about 3 times longer than wide and only slightly longer than the anal somite, and the outerlateral seta on the ramus is positioned subdistally. In addition, the protopod of leg 5 has an elongate digitiform outer process and distinctly spiniferous inner margin, and the exopodal segment is suboval with a strong inner spine. These characteristic features of N. elegans are present in our material from the Adriatic Sea. The species was originally reported from Swedish waters (Thorell, 1859) and its known distribution extends from Scandinavia, along the coast of northwestern Europe and into the Mediterranean (Illg, 1958; Illg & Dudley, 1961).