Genus Perepsilonema Lorenzen, 1973

Type species: Perepsilonema papulosum Lorenzen, 1973 [Clasing, 1984] Other species:

Perepsilonema bahiae (Gerlach, 1957) Lorenzen, 1973 syn. Bathepsilonema bahiae Gerlach, 1957 P. c r a s s u m Lorenzen, 1973

P. trauci Lorenzen, 1973

P. c o n i f e r Lorenzen, 1973 syn. P. conifer lissum (Lorenzen, 1973) op. Gourbault & Decraemer 1988 P. corsicum Vanreusel & Vincx, 1986

P. mediterraneum Vanreusel & Vincx, 1986

P. longispiculosum Vanreusel & Vincx, 1986

P. coomansi Vanreusel & Vincx, 1986

P. tubuligerum Gourbault & Decraemer 1988

P. kellyae Gourbault & Decraemer, 1988 [Verschelde & Vincx 1994] P. m o i n e a u i Gourbault & Decraemer, 1992

P. r i t a e Verschelde & Vincx, 1994

P. benguelae sp. nov.

General remarks. A revised taxonomic key to males of the species of the genus is provided: modified from Gourbault and Decraemer (1988).

1 Six subcephalic setae .................................................................................................................................................... 2 Eight subcephalic setae ................................................................................................................................................. 3

2 Two fields of poorly developed copulatory thorn-like structures, one in ventral fold, second at level of testis; a few small spines in cloacal region; spicule 68–77 μm long ........................................................................... P. tubuligerum Two fields of well-developed copulatory thorn-like structures, one at level of testis, second as precloacal thorns; spicule 31–32 μm long ..................................................................................................................................... P. conifer

3 Six subcephalic setae on cephalic capsule anterior to amphid; two setae at base of amphid inserted on first annulus. ...................................................................................................................................................................................... 4 Eight subcephalic setae anterior to amphid .................................................................................................................. 7

4 Copulatory thorns absent .............................................................................................................................................. 5 Copulatory thorns present at level of testis or in cloacal region................................................................................... 6

5 Annulations with numerous small vacuoles ............................................................................................. P . papulosum Annulations with minute vacuoles and additional dorso-longitudinal striations ......................................... P. moineaui

6 Annulations plain; one pair of large copulatory thorn-like structures plus 4 pairs small copulatory thorns in midbody region ...................................................................................................................................................... P. kellyae Annulations with regular vacuoles; three pairs of copulatory thorn-like structures in precloacal region ...................... ...................................................................................................................................................... P. benguelae sp. nov.

7 No copulatory thorn-like structures at the enlargement of the median body ................................................... P . bahiae Copulatory thorn-like structures at the enlargement of the median body..................................................................... 8

8 Two rows of small thorns subdorsally on caudal annulations ...................................................................................... 9 Two fields of small spines subdorsally on caudal annulations ................................................................................... 11

9 Body annulations ornamented with tiny, barely visible vacuoles .................................................................. P . crassum Body annulations with a single row of large vacuoles ............................................................................................... 10

10 Two fields of subventral copulatory thorn-like structures: 5 pairs at level of testis, and 3 pairs in precloacal region... .......................................................................................................................................................................... P . trauci Ventral field of tiny spines in region between dorsal and ventral body curvature; two pairs large copulatory thorns at level of testis ........................................................................................................................................................ P. ritae

11 Single field of three pairs of subventral copulatory thorn-like structures at level of testis; no precloacal thornlike structures ..................................................................................................................................................................... 12 Two fields of copulatory thorn-like structures at level of testis and in precloacal region .......................................... 13

12 Copulatory thorn-like structures well developed; spicule 64 μm long ............................................. P . longispiculosum Copulatory thorn-like structures poorly developed; spicule 39 μm long .................................................... P. corsicum

13 Six to seven pairs of subventral copulatory thorn-like structures in testis region; two pairs copulatory thorns in precloacal region; cephalic capsule as wide as long ................................................................................ P . mediterraneum Three pairs of subventral copulatory thorn-like structures in the testis region, followed by subventral pair and a single thorn in ventral region anterior to vas deferens, another two pairs subventrally in precloacal region; cephalic capsule longer than wide ................................................................................................................................... P. coomansi