Eulimella Forbes & McAndrew, 1846

Høisaeter, Tore, 2014, The Pyramidellidae (Gastropoda, Heterobranchia) of Norway and adjacent waters. A taxonomic review, Fauna norvegica 34, pp. 7-78 : 55-56

Eulimella Forbes & McAndrew, 1846

Type species, by original designation: Eulimella macandrei ( Forbes, 1844) (See van Aartsen 1988 and Warén 1991).

Pyramidellids with elongated, slender, many-whorled shells. Shell usually white, semitransparent and polished, and smooth or with delicate lines of growth (and sometimes extremely fine spiral lirations). Columellar fold either absent or a very low and indistict thickening on the nearly straight inner lip. Protoconch medium-sized to large, either helicoid or planorboid, with an angle of inclination of 80° to 130°. The protoconch base is fully exposed and the spire only slightly immersed in the teleoconch. Height of first postlarval whorl 110 - 205 µm. Ratio of diameter of protoconch to diameter of first postlarval whorl between 0.70 and 0.85. Operculum lightly horn-coloured, thin and transparent with small excentric spire, and a narrow internal, spiral ridge.

For some reason, Dall & Bartsch (1904) include among the generic characters the presence of two columellar folds (’teeth’). This misconception has been arrested by practically every later author, and it has caused no great problems for the taxonomists. For the European forms, Jeffreys (1884) distinguished between shells having a distinct columellar fold, and those without. Thus he described a species, Odostomia praelonga , that in every respect fits the diagnosis of Eulimella except for the presence of a distinct tooth on the columella. Monterosato (1884) and Fischer (1887) both regarded the absence of a columellar fold as an importent diagnostic character for this group. Nordsieck (1972) collected all elongated, unsculptured species with an exposed, heterostrophic protoconch in the subfamily Eulimellinae .

Recently the North European species of the genus were monographed by Warén (1991), who recognised three formerly described species, and introduced one new species, Eulimella ataktos . Van Aartsen (1994) reviewed all European species of the group. He followed G.O. Sars (1878) in separating E. compactilis from E. scillae , a decision disputed by Warén (1991). However van Aartsen did not mention Warén’s E. ataktos . In this paper all five species are accepted, and a new species is added ( Eulimella frielei ) bringing the total for Norwegian waters to six species.

Key to the species of Eulimella , based on shell morphology

1a. Shell solid, porcellaneous, a perfect cone with flat whorls, suture very shallow, periphery distinctly angulated ................................................ Eulimella scillae

1b. Shell flatsided, channeled suture, delicate translucent shell, periphery rounded ..... Eulimella compactilis

1c. Shell different ..................................................................2

2a. Protoconch helicoid ................................ Eulimella laevis 2b. Protoconch more or less planorboid ................................3 3a. Shell extremely long and thin, protoconch helicoid

at 135° ...................................................... Eulimella frielei 3b. Shell different ................................................................4

4a. Shell narrow, H/W ratio 2.8 to 3.0 with 7 whorls,

whorls convex, protoconch planorboid ...................... Eulimella ventricosa

4b. As E. ventricosa , but H/W ratio around 2.5 with 7

whorls .................................................... Eulimella ataktos