Contr. Tert. Quatern. Geol. 34(1-2) 9-29 1 tab., 4 pis. Leiden, March 1997 Pliocene gastropod faunas from Kallo (Oost-Vlaanderen, Belgium) — Part 2. Caenogastropoda: Potamididae to Tornidae R. Marquet Antwerp, Belgium Marquet, R. Pliocene gastropod faunas from Kallo (Oost-Vlaanderen, Belgium) — Part 2. Caenogastropoda: Potamididaeto Tornidae. — Contr. Tert. Quatern. Geol., 34(1-2): 9-29, 1 tab., 4 pis. Leiden, March 1997. Elements of the caenogastropod fauna from Pliocene strata exposed at Kallo, province of Oost-Vlaanderen (Belgium), are described and illustrated, and their stratigraphical and geographical occurrence discussed. Ten species not recorded previously from the Pliocene Turritella Brakman, 1937, of Belgium are described, viz. Tenagodus obtusus (Schumacher, 1817) s. lat., (Haustator) vanderfeeni Littorina (Melaraphe) gibbosa Etheridge & Bell, 1893, Onoba aff. millettii (Etheridge & Bell, 1893), Onoba semicostata (Montagu, 1803), Rissoa (Turboella) curticostata Wood, 1848, Obtusella intersecta (Wood, 1856), Skeneopsis planorbis (Fabricius, 1780), Caecum glabrum (Montagu, 1803) and Ceratia proxima (Forbes & Hanley, 1850). Alvania (A.) simonsi and Peringiella crassilabris are described as new. Another species previously unknown from the Belgian Pliocene, Alvania (A.) whitleyi (Bell, 1898), is recorded from Antwerp-Oorderen. Key words — Gastropoda,1 Caenogastropoda, Pliocene, North Sea Basin, taxonomy, stratigraphy, new species. Dr R. Marquet, Constitutiestraat50, B-2060 Antwerpen, Belgium. Contents SYSTEMATIC DESCRIPTIONS Supcrorder Caenogastropoda Cox, 1960 Introduction p. 9 Order Neotaenioglossa Haller, 1882 Systematic descriptions p. 9 Suborder Discopoda Fischer, 1886 Acknowledgements p. 20 Cerithioidea de Ferussac, 1819 References 20 Superfamily p. Family PotamididaeH. & A. Adams, 1854 Subfamily PotamidinaeH. & A. Adams, 1854 Genus Potamides Brongniart, 1810 Subgenus Ptychopotamides Sacco, 1895 Introduction Potamides (Ptychopotamides) tricinctus The harbour construction works at Kallo, and the (Brocchi, 1814) stratigraphy of the Pliocene deposits exposed, have PI. 1, Fig. 2 recently been described in detail by Marquet (1995). The is two series to present paper part of a of papers devoted 1814 Murex tricinctus Brocchi, p. 446, pi. 9, fig. 23. a systematic revision of the Pliocene gastropod faunas 1835 Br. — 27. Cerithium tricinctum Nyst, p. from Kallo. the Especially amongst Rissoidae, a species- 1843 Cerithium funiculatum Sow. — Nyst, p. 539, pi. rich here recorded for the first family, many taxa are 42, fig. 8. time from the Pliocene. These were 1848 tricinctum ? Brocc. — 69, Belgian mostly Cerithium Wood, p. pi collected from the sediment infillof larger gastropods. 8, figs 1, 2. 10 1878 Cerithium tricinctum, Brocchi — Nyst, pi. 6, fig. Description — Medium-sized vermiform shell, with 10. tubes in part loosely coiled and in part straight, not 1881 Cerithium tricinctum, Brocchi — 79. Nyst, p. forming colonies. Aperture is rounded. A faint keel 1918 Potamides tricinctus (Ptychopotamides) (Brocchi) whorls. to this keel, occurs on the upper part of the Next — 22-25. Harmer, p. 411, pi. 40, figs closest to the suture, perforations occur. Ornament 1946 Potamides (Ptychopotamides) tricinctus (Brocchi, consists of very irregular radial ribs. — 43. 1814) Beets, p. Discussion — This species is extremely rare in the 1958 Potamides (Ptychopotamides) tricinctus Brocchi, Petaloconchus bed (Kattendijk Formation), the first 1814 — 6. sp. Glibert, p. specimen having been collected by Mr F. van Nieulande. 1965 Potamides tricinctus (Brocchi, 1814) — van beach and material from the the Altena In dredged Netherlands, Regteren et al., p. 17, pi. 6, fig. 59. had been earlier 1992 Potamides (Ptychopotamides) tricinctus (Brocchi, species recognised (van Regteren — Cavallo & 48, 60. Altena, 1966; and Keukelaar 1814) Repetto, p. fig. Marquet Collections). 1993 Potamides tricinctus (Brocchi, 1814) — Marquet, Pliocene specimens from Italy were illustrated by 90. Miocene p. Cavallo & Repetto (1992), while material of from the Loire Basin described age (France) was as Dimensions — Height 16 mm, width 6 mm. Tenagodus terebellus (Lamarck, 1818) and figured by — Medium turreted shell Description large, lacking Glibert (1949). Dutch material was assigned with a recticonical whorls with umbilicus, comprising ten van Altena query to the latter species by Regteren shallow suture. The lacks a canal, but aperture siphonal (1966), the difference between the two taxa being is intact. Ornament consists of three Miocene is rarely preserved mainly one of dimensions. The species spirals on the last whorl, crossed by radial ribs, giving smaller than its Pliocene congener. This, however, is rise to tubercles on the points of intersection of spirals considered to be insufficient for separation at the and ribs. specific level; a distinction at the subspecific level might Discussion — At Kallo, this is rare in the The Kallo illustrated here species be more appropriate. specimen Merksem Member, found more in the being commonly is of the same size as shells from Touraine (France), but Austruweel Member near which Kallo and from Antwerp, probably a fragment from a complete specimen with the benedeni level at Kallo. It corresponds Angulus dredged material dumped at Yerseke (The Netherlands) does this level of the Oorderen Member not occur at at (Keukelaar Collection) are much larger. Not until more water nor is it of the Kallo, representing deeper deposition, material is found, is a subspecific assignment known from the Kruisschans Member. Presumably, P. North Sea Basin shells possible. tricinctus was restricted to estuarine conditions, which explains its occurrence in the Austruweel Member. This also Ellobiidae and land nearshore deposit yields many Family TurritellidaeLoven, 1847 snails. The species has also been recorded from the Subfamily Turritellinae Loven, 1847 middle and late Pliocene of Italy and the North Sea Genus and Basin. subgenus TurritellaLamarck, 1799 Family Siliquariidae Anton, 1838 Turritella(Turritella) tricarinata tricarinata Genus Tenagodus Guettard, 1770 (Brocchi, 1814) PI. 1, Fig. 5 obtusus lat. Tenagodus (Schumacher, 1817) s. 1814 Turbo tricarinata 21. Brocchi, p. 374, pi. 6, fig. PI. 4 — 3, Fig. 1878 Turritella incrassata var. triplicata J. Sow. Nyst, pi. 6, fig. 12. 1817 262. 1912 Turritella tricarinata Br. — Cerulli-Irelli, Anguinaria obtusa Schumacher, p. sp. p. 1896 Tenagodus anguineus (Schumacher, 1817) — 158, pi. 26, figs 20-25. 14-18. 1912 tricarinata Br. anom. Sacco, p. 17, pi. 2, figs Turritella sp. bicingulata — 27. 1966 Tenagodus spec. cf. terebellus (Lamarck, 1818) Cerulli-Irelli,p. 159, pi. 26, figs 26, 2. 1912 tricarinata Br. anom. van Regteren Altena, p. 62, fig. Turritella sp. pluricingulata — Cavallo 29. 1992 Tenagodus obtusus (Schumacher, 1817) Cerulli-Irelli, p. 159, pi. 26, figs 28, & 48, 063 1918 Turritella tricarinata (Brocchi) — Harmer, p. 438, Repetto, p. fig. pi. 44, figs 7-9. — 1958 Brocchi, Dimensions Height 7 mm, width 5 mm. Turritella (Haustator) tricarinata sp. 11 1814 — 1. Glibert, p. 4, pi. 2, fig. number of very fine spirals. Some specimens have a 1965 Turritella (Turritella) tricarinata tricarinata faint keel at whorl mid-height. Brocchi, 1814 — van Regteren Altena et al., 16, p. Discussion — At Kallo, this species is confined to the 5, fig. 52a. pi. Petaloconchus bed of the Kattendijk Formation, this Turritella tricarinata — 1990 (Brocchi) Bernasconi, p. being the first record from Belgium. Most of the 32, pi. 1, figs 1-2. specimens known so far were collected from Dutch 1992 Turritella (Turritella) tricarinata Brocchi, 1814 — beach material (province of Zeeland). Most authors Cavallo & 64. Repetto, p. 50, fig. consider the present taxon to be but a variety of T. incrassata. However, the specific features displayed by Dimensions — 30 width 9 Height mm, mm. T. vanderfeeni remain constant, and intermediates with Description — Medium large, turreted shell lacking T. incrassata are not found: it differs from the latter in umbilicus, comprising about 13 whorls. Protoconch having a relatively wider shell, an extremely shallow consists of two and a halve tumid, smooth and glossy suture and in lacking stronger primary ribs. At Antwerp- whorls, the boundary with the teleoconch being clearly Noordkasteel, typical T. incrassata is known from the delimited. The aperture is rounded quadrangular. The Ditrupa bed of the Kattendijk Formation. It thus appears whorls are rather tumid and the suture deep. On each that these species possibly co-occurred, but final proof is whorl two or three spirals occur, exceptionally with a still outstanding. The species is restricted to the early secondary rib in between. The central spiral is usually Pliocene of the North Sea Basin. developed best, but the relative strength of the spirals varies to some degree. Discussion — This species ranges from the Kattendijk Turritella (Haustator) incrassata incrassata Formation to the Kruisschans Member, but is never J. Sowerby, 1814 common. In the former unit it occurs about 0,5 m above PI. 1, Fig. 3 the Petaloconchus bed, where it replaces T. vanderfeeni (see below). It differs from its Kallo congeners in having 1814 Turritella incrassata Sowerby, p. Ill, pi. 51, fig. tumid whorls and in a deep suture, lacking secondary 4. ornament. The species is known from the Pliocene of the 1843 — Turritella triplicata Br. Nyst, p. 400, pi. 37, North Sea Basin and the Mediterraneanarea. figs 7, 8. Turritella incrassata J. Sow. — 1848 Wood, p. 75, pi.