Vitreotubus Zibrowius, 1979

Genus Vitreotubus Zibrowius, 1979 View in CoL

Type species. Vitreotubus digeronimoi Zibrowius, 1979 View in CoL

Generic diagnosis (from ten Hove & Kupriyanova, 2009). Tube entirely vitreous, more or less quadrangular in cross-section by its two large undulating lateral keels, and with a median keel made of a row of teeth. Operculum inverse conical with chitinous diabolo-like endplate. Peduncle smooth, cylindrical, merging gradually into operculum, without wings, inserted as first radiole. Pseudoperculum absent. Arrangement of radioles short pectinate, up to 11 per lobe. Inter-radiolar membrane and stylodes absent. Radiolar eyes not observed. Mouth palps present. Seven thoracic chaetigerous segments. Collar trilobed. Medial lobe of collar with scalloped edge and lateral projections, separated from lateral lobes by deep incision (tonguelets absent), latter continuous with thoracic membranes extending all along thorax, but narrow in posterior segments, forming ventral apron. Collar chaetae Spirobranchus View in CoL - type and simple limbate. Apomatus View in CoL chaetae absent. Thoracic uncini saw-shaped with 6–7 teeth above pointed fang. Triangular depression present.Abdominal chaetae true trumpet-shaped, with two rows of pointed teeth bordering hollow groove and extended into a long lateral spine. Abdominal uncini saw-shaped with about 6 teeth anteriorly, rasp-shaped with about 10 teeth in profile, 3–4 teeth in a row posteriorly. Achaetous anterior abdominal zone absent. Posterior capillary chaetae absent, but geniculate chaetae long at end of abdomen. Posterior glandular pad absent.

Remarks. The monotypic genus was originally described from fossil records and Recent material collected in the bathyal zone off the Azores and in the Indian Ocean ( Zibrowius, 1979), more recent records are given by ten Hove (1994).