Family CERITELLIDAE Wenz, 1940 (Fig. 2 B-M) Ceritellidae Wenz, 1940: 817. — Pchelintsev 1965: 9. (pars). Tubiferidae Cossmann, 1896: 12 (pars). Diptyxisidae Pchelintsev, 1965: 79 TYPE GENUS. — Ceritella Morris & Lycett, 1854 [1854: 37]. TYPE SPECIES. — C.acuta Morris & Lycett,1854 [1854:37]). FAMILY CHARACTERS. — Shells medium size to large, broad turriculate or high oviform. Whorls convex, smooth or with collabral or spiral sculpture (in Proceritella Fischer, 1961). Periphery of last whorl rounded to angular, narrow umbilicate or anomphalous. Aperture semicircular, with siphonal notch, forming a siphonal aureole in umbilicate taxa and a beak in others. Small columellar plait disappearing towards aperture, restricted to the aperture in Fibuloptyxis bucillyensis Fischer, 1959. Strong palatal plait or parietal plait. REMARKS Cossmann (1895a) considered Ceritella as synonymous with Tubifer Piette, 1856. In the latter, the aperture is higher and a distinct subsutural ramp is developed. It therefore represents a different genus (see Gründel & Nützel 2012). Figure 2 B-I demonstrates the high diversity of this family. It comprises taxa with more or less broad turriculate shells (Fibuloptyxis Cossmann, 1898; Proceritella Fischer, 1961) or with strongly inflated final whorls (Pseudotrochalia Cox, 1954). Diptyxis Oppenheim, 1889 is allocated to the Ceritellidae because of its siphonal notch and the internal plication with its large parietal plait and a small columellar plait. The periphery is rounded angular to angular. The genus was established by Oppenheim (1889), who figured a fragment from the island of Capri under Nerinea (? Diptyxis) biplicata (the question mark is part of the original identification). Oppenheim neither discussed the new subgenus nor did he comment on the question mark. Actually, Oppenheim’s species is a younger synonym of Nerinea bidentata Gemmelaro, 1865. There is no reason to retain the family Diptyxidae Pchelintsev, 1965 (described as “Diptyxisidae” by that author) with Nerinea csaklyana Herbich, 1886 as type species. Extreme by its size is the type species of Cossmannea Pchelintsev, 1931, C. desvoidy (d’Orbigny, 1851) (Fig. 2B, C; see also Wieczorek 1979). Originally assigned to Nerinea Deshayes, 1827, Cossmannea possesses a rounded angular whorl periphery, a broad palatal plait and lacks a siphonal canal. It must therefore be allocated to the Ceritellidae. Most of the taxa allocated in the literature to Cossmannea, however, remain within the Eunerineidae n. fam. Despite its trochiform shell, which made Cossmann (1898) doubt its systematic position in the Nerineoidea, the aperture identifies Aphanoptyxis Cossmann, 1896 (synonymous: Endiatrachelus Cossmann, 1898, see Fischer 1969) as a genuine Ceritellidae taxon. In the type species, A. pellati Cossmann, 1898, the aperture is incomplete and the base appears to be rounded. Complete specimens show the basal notch (Fig. 2 K-M). (Austria),NHMW 2013/0266/0001; I, Ptygmatis bruntrutana (Thurmann, 1832),enlarged whorl section showing cross sections through the duct system, Kimmeridgian, Alenquer (Portugal); NHMW 1869-X-30. Scale bars: A, D, H, 5 mm; B, C, E-G, I, 10 mm.

Published as part of Kollmann, Heinz A., 2014, The extinct Nerineoidea and Acteonelloidea (Heterobranchia, Gastropoda): a palaeobiological approach, pp. 349-383 in Geodiversitas 36 (3) on pages 354-355, DOI: 10.5252/g2014n3a2, http://zenodo.org/record/4538503