Zootaxa, Taxonomy of Serpulidae (Annelida ... - Magnolia Press

absent. Thoracic uncini saw-to-rasp-shaped with numerous teeth (> 12) in profile, 2–3 teeth per row (dental
formula P:3:3:3:2:2:1:1:1:1:1:1:1:1); anterior peg gouged (Pomatoceros type) (Fig. 31B). Abdominal chaetae
short, with flat triangular denticulate blade (Fig. 31D). Thoracic triangular depression absent. Abdominal
uncini similar to thoracic ones (Fig. 31C). Achaetous anterior abdominal zone absent. Long posterior capillary
chaetae absent. Posterior glandular pad absent.
Remarks. The diagnosis above is based on the description of the only Recent species thus far described -
from specimens collected at depths of 1846–1900 m off the Azores. Topotypical material from 2440 m is
present in the collections of the ZMA (V.Pol. 3906, presented by H. Zibrowius), additional material from the
Central Atlantic was mentioned by Hartman & Fauchald (1971), they, however, counted 4 thoracic chaetigers
only. A possible second undescribed species was found at 4124 m south-east off the Galapagos Islands (ZMA
V.Pol. 3859). Zibrowius (pers. comm.) suspects a total of 4 different species, partly with not coiled
quadrangular tubes.
Jäger (2004) synonymized the Recent genus Spirodiscus Fauvel, 1909 with the Fossil Nogrobs de
Montfort, 1808. Jäger also suggested that the Recent Bathyditrupa hovei might belong to the subgenus
Nogrobs (Tetraditrupa) Regenhardt, 1961, without further argumentation.
Nogrobs grimaldii (Fauvel, 1909), Central Atlantic, off Azores; bathyal, abyssal.
26. Omphalopomopsis Saint-Joseph, 1894
(Fig. 7A, B)
Type-species: Omphalopoma langerhansii Marenzeller, 1885
Number of species: 1
Tube subcylindrical, white, opaque, with 3 denticulate keels and an occasional low collar-like ring. Granular
overlay not observed. Operculum bulbous with slightly convex brilliantly white calcareous endplate. Peduncle
cylindrical, broadening and wrinkled towards opercular ampulla, constriction present; without wings;
insertion unknown. Pseudoperculum not mentioned in original description, presumably absent. Up to 25 pairs
of radioles, arranged in two circles/short spires. Inter-radiolar membrane absent. Branchial eyes, stylodes, and
mouth palps not observed. 7 thoracic chaetigerous segments. Collar trilobed, well developed, especially
medio-ventrally; thoracic membranes wide till 3 rd segment, further unknown (damaged), apron apparently
absent. Tonguelets unknown. Collar chaetae bayonet-like with numerous hair-like processes basally,
Spirobranchus-type and limbate. Apomatus chaetae present. Thoracic uncini saw-shaped, with 7–8 teeth
above anterior pointed fang. Triangular depression unknown. Abdominal chaetae geniculate, SEM details
unknown, probably Vermiliopsis-type (then flat narrow geniculate), apparently with almost smooth edge, very
long posteriorly. Uncini saw-shaped anteriorly with 7 teeth and fang, rasp-shaped posteriorly. Achaetous zone
not known. Long posterior capillary chaetae present. Posterior glandular pad not observed.
Remarks. The taxon is known only from the single holotype deposited in the Natural History Museum of
Vienna, NHMW A.N.14552, Inv. no. 2054 (Fig. 7A, B). The description by Marenzeller (1885) leaves doubt
about the shape of the anterior uncinal tooth, it may be either pointed as in Hydroides, or blunt as in
Vermiliopsis.
Specimens attributed to Omphalopomopsis by Fauvel (1930, 1953) and Pillai (1960) in reality belong to
Pomatostegus actinoceras (fide Zibrowius (1973b), as P. stellatus).
Omphalopomopsis langerhansii (Marenzeller, 1885), South Japan, Enoshima, 366 m.
TAXONOMY OF SERPULIDS: STATE OF AFFAIRS
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