Anoplodelphys africana n. sp.

Type material: Holotype female in alcohol, and 1 complete, plus 1 incomplete (posterior half only) paratype females. Registration nos: MNHN-Cp2323 (holotype), MNHN-Cp2313 (dissected paratype mounted on 1 slide), MNHN-Cp2314 (incomplete paratype in alcohol).

Type Locality: Gulf of Suez (Collector—Dollfus; 22.12.1928).

Host: Didemnum sp. [MNHN reg. no. A2 DID C 322]

Locality in host: within the common tunic between the zooids (F. Monniot, pers. comm.)

Etymology: the new species is the first Anoplodelphys to be described from the African continent.

Description: Adult female body (Fig. 1 A–B) highly transformed, vermiform and lacking expressed external segmentation: divided into 3 regions, cephalosome, metasome and urosome, by shallow superficial furrows. Entire body surface densely ornamented with relatively short setules (Fig. 1 D). Body length of holotype female 2.17 mm. Cephalosome slightly dorsoventrally flattened, tapering anteriorly; bearing paired antennules, antennae, and 2 pairs of lobes which probably represent reduced and modified oral appendages. Lateral margins of head expanded ventrally to form ridge-like swelling produced into thumb-like process at posterior extremity (Fig. 2 A). Rostrum well developed (Fig. 1 C), distinctly bilobed, located in midline on frontal margin of cephalosome. Metasome more or less cylindrical, slightly narrowing anteriorly, comprising 4 somites with boundaries marked by superficial integumental folds; first 2 somites only pedigerous, each bearing pair of modified, biramous thoracic legs. Urosome (Figs 1 A–B, 2D–E) reduced and largely invaginated into pocket in posterior margin of metasome (Fig. 2 D–E). Urosome lacking expressed segmentation; incorporating caudal rami (Fig. 2 E). Surface of urosome and incorporated caudal rami ornamented with surface setules, cuticular folds and numerous small pores; lacking trace of caudal setae.

Antennules (Figs 1 C, 2A) inserted just lateral to rostrum; divided into swollen basal part bearing 3 rounded processes, orientated anteriorly, laterally and posteroventrally, and conical, tapering distal part armed with 5 setal elements, 4 apical and 1 subapical (Fig. 1 E). Surface of antennule ornamented with scattered setules, most dense on basal processes.

Antenna (Fig. 2 B) 2-segmented: proximal segment, robust, triangular in shape and largely concealed between lateral cephalosomic process and prominent antennomedial lobe located just posterior to base of antenna on ventral surface of cephalosome (Figs 1 C, 2A): distal segment forming strongly sclerotised subchela, ornamented with few small marginal denticles near tip (Fig. 2 C).

Labrum (Fig. 1 C) fleshy, forming massive tapering cone, with rounded tip reaching back to anterior bor- der of second legs. Surface of labrum densely ornamented with setules.

Oral appendages (Figs 1 C, 2A) reduced. Two pairs of small rounded processes present; 1 pair (?mandibles) lying just anterior to frontal margin of labrum, second pair (?maxillules) located lateral and posterior to first pair. Additional pair of sclerotised plates (see inset Fig. 1 C) with transverse opening located immediately adjacent to base of labrum.

Legs 1 and 2 present (Fig. 1 A–C), legs 3 and 4 absent. Leg 1 originating posterior and lateral to base of labrum; leg 2 originating slightly closer to midline. Each leg biramous, with unsegmented, lobate rami forming elongate conical processes, lacking recognisable setal armature but densely ornamented with surface setules. Exopodal and endopodal lobes about equal in size, arising from common protopodal part, largely incorporated into somite.

Leg 5 not observed.

Male unknown.

Remarks: The new species differs from Anoplodelphys corneci Lafargue and Laubier, 1978, A. galli and A. incerta in the presence of only the first two pairs of swimming legs rather than four pairs. It also differs in the bilobate condition of the rostrum and in having a swollen basal part to the antennule which is produced into three distinct processes.

The paired lobes in the oral region are here interpreted as representing reduced and modified mouthparts. The anterior pair, from its similar position to the mandibles present in Brementia balneolensis, is probably the mandibles, with each reduced to palp remnants. The posterior pair is interpreted as possible maxillules. The paired sclerotised plates may represent a vestige of the maxillae, since the transverse, slit-like opening may belong to the maxillary glands.