Scaptognathus trouessarti Halbert, 1915

Diagnosis. Glp-1 not distinct. Ds-2 on membranous cuticle. PE with 1 dorsal seta. GA bipartite in male. Male with 32 Pgs. Tr I–IV with 1-1-1-1 setae; Bf I–IV with 2-2-1-1 setae; Tf I–IV with 4-4-3-2 setae, 2-1-0-0 Bp setae; Gn I–IV with 4-3-2 (3?)-3 setae, 2-1-0-0 Bp setae; Tb I–IV with 8-6-7-7(8?) setae, 5-3-4-4 Bp setae; Ta I–IV with 3-3-3-3 dorsal setae, without Bp setae. Lc I with unidentate accessory process. Idiosoma length 436 in male (holotype). Idiosoma width 284 in male (holotype). Gnathosoma length 284 in male (holotype). Gnathosoma width 132 in male (holotype). Ratio of gnathosoma to idiosoma 0.65 in male (holotype). Ratio of P-2 to P-1 4.10 in male (holotype).

Remarks. This species resembles S. triden s and S. hallezi, however, differs from these two species by the round posterior margin of AD, Ds-2 on membranous cuticle, convex anterior margin of pars sclerosum in male, 32 Pgs in male, and leg chaetotaxy. Single male is known.

Habitat. Sublittoral zone: Fine gravels at a depth of 35–39 m. Fronds and holdfasts of Laminaria ochroleuca (Phaeophyta).

Distribution. North Atlantic Ocean: Dingle Bay [Ireland]. Mouro Is. (43°28’24’’N, 3°45’22’’W) [Spain].

References. Abé (1990c), Abé & Green (1994), Abé & O’Connor (1991), Bamber (1982), Bartsch (1994b), Bartsch & Schmidt (1978), Green & Macquitty (1987), Halbert (1915), Riesgo et al. (2010).

Depository. NMID.