Diagnosis: head long; interbranchial septa with a median posteriorly projecting lobe for a distance about equal to two spiracle diameters across the second to the fifth gill openings. First dorsal fin only a little smaller than second dorsal fin; origin of first dorsal fin slightly in advance of the posterior end of the pelvic fin base. Colour: uniformly blackish-brown. Size: to 68 cm (male) or 66.8 cm (female).
Habitat: benthic at 600-800 m. Food: no data. Reproduction: oviparous; the holotype had two horny egg capsules with more than 20 longitudinal striations.
Distribution: off Madeira. Possibly also from Iceland, Bill Bailey's, Lonsy and Great Sole Banks, eastern North Atlantic slope (Compagno, 1985).
Apristurus maderensis Cadenat & Maul, 1966: Bull. Inst. fr. Afr. noire, (A) 28 (2): 769, fig. 1-4 (Madeira). Holotype: MMF no. 18750.
Cadenat, J.; Maul, G. E. 1966. Note d'Ichtyologie ouest-africaine. XLIII. Description d'une espèce nouvelle du genre Apristurus, Apristurus maderensis. Bull. Inst. fond. Afr. noire, (A) 28 (2): 769-782, 4 fig.
Compagno, L. V. J. 1984-1985. FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of sharks species known to date. FAO Fish. Synop, (125) 4, pt 1 (1984), Hexanchiformes to Lamniformes: 1-249; pt 2 (1985), Carcharhiniformes: 250-655.