Bathyfauvelia Pettibone, 1976: 34. – Barnich & Fiege, 2003: 90.
Type species: Macellicephala affinis Fauvel, 1914a.
Diagnosis (emended): Short body, dorsoventrally flattened, up to 21 segments. Prostomium bilobed. Frontal filaments present (Bathyfauvelia affinis) or absent (Bathyfauvelia glacigena sp. nov. and Bathyfauvelia ignigena sp. nov.). Eyes absent. Median antenna present, lateral antennae absent. Facial tubercle absent. Tentaculophores with acicula and chaetae. Pharynx with two pairs of jaws; serrated margins with nine pairs of pharyngeal papillae. Dorsal tubercles forming cirriform to lamelliform branchiallike processes. Elytrophores large, up to nine pairs, on segments 2, 4, 5, 7, 9, 11, 13, 15 and 17. Parapodia subbiramous, notopodia shorter than neuropodia; noto- and neuropodia with elongate acicular lobe; tips of noto- and neuroaciculae not penetrating epidermis. Notochaetae stout, distally with spinous rows; notochaetae stouter than neurochaetae. Neurochaetae distally flattened to concave, serrated along both margins. From segment 3, ventral cirri inserted medially on neuropodia. Nephridial papillae present, small. Pygidium rounded, with dorsal anus.
Remarks: The diagnosis of genus Bathyfauvelia is emended to include characters observed in the new species described below. These include: absence of frontal filaments and presence of serrated jaws. Pettibone (1976) considered valid only two species in this genus, but a few inconsistencies were observed from the drawings of the Arctic and Mediterranean specimens of Bathyfauvelia affinis (Pettibone, 1976: 36–37, figs 21, 22). The specimen from the Arctic Basin shows an elongated acicular lobe in the tentacular segment without chaetae and shorter prostomium lobes, whereas the specimen from the Mediterranean Sea shows a shorter acicular lobe in the tentacular segment with chaetae and slightly longer prostomium lobes.