Eulima ephamilla Watson 1883

Eulima ephamilla Watson, 1883

(Figure 5 A–E)

Eulima ephamilla Watson, 1883: 116–117. Watson (1886: plate 35, figure 6a–c).

Eulima (“ Liostraca ”) stenostoma auct. non Jeffreys, 1858: Dall (1889a: 126).

Eulima (Leiostraca) rectiuscula Dall, 1890: 160 (in part).

Melanella ephamilla (Watson, 1883): Lange-de-Morretes (1949: 82); Rios (1994: 103, plate 34, figure 426 [reproduced from original illustration]); Rios (2009: 191, figure 468 [reproduced from original illustration]).

Balcis ephamilla (Watson, 1883): Rios (1975: 61, plate 16, figure 239 [reproduced from original illustration]); Rios (1985: 54, plate 20, figure 242 [reproduced from original illustration]).

Type material. Lectotype (herein designated): NHMUK 1887.2.9.1589 (Figure 5A, B). Paralectotypes (herein designated): NMW 1955.158.11088 [2 dd] (Figure 5C), from type locality. Holotype of Eulima rectiuscula Dall, 1890: USNM 87343 (Figure 5D, E), USFC stn. 2668 (30°58′30″N 79°38′30″W, 538 m), coll. 05/v/1886.

Type locality. Brazil: off Pernambuco, Challenger stn. 122.

Material examined. Type material.

Measurements. Lectotype NHMUK 1887.2.9.1589, ~10 whorls (protoconch broken), SL= 8.5 mm; BWL= 3.4 mm; AL= 2.1 mm; SW= 1.8 mm; AW= 1.2 mm. Paralectotype NMW 1955.158.11088, ~10 whorls (protoconch broken), SL= 6.3 mm; BWL= 2.7 mm; AL= 1.6 mm; SW= 1.4 mm; AW= 0.9 mm. Paralectotype NMW 1955.158.11088, ~10 whorls (apex and aperture broken), SL= 8.0; BWL= 3.3 mm; AL= 1.6 mm; SW= 1.7 mm; AW= 0.9 mm. Holotype of Eulima rectiuscula, USNM 87343, ~8 whorls (apex broken), SL= 9.6; BWL= 4.0 mm; AL= 2.4 mm; SW= 2.0 mm; AW= 1.3 mm.

Remarks. The shell numbered NHMUK 1887.2.9.1589 (Figure 5A, B) is the figured specimen by Watson (1886: plate 35, figure 6a–c) and is here designated as the lectotype. There are two other shells from the type locality stored in the NMW (NMW 1955.158.11088), which are here considered as paralectotypes. Watson (1883: 116) cited that “the specimen is dead and discoloured”, which could indicate that he referred to a single shell. However, Watson (1883) did not designate holotypes in his descriptions, and as other shells from the same locality were found, we prefer to consider that all were originally syntypes. See discussion for the status of types in the NMW. Watson’s (1883) description is appropriate to the lectotype and there is no need for a redescription. We only add that there is no presence of an umbilical fissure as stated by him in describing a “very minute furrow” behind the inner lip.

Eulima ephamilla presents the general shape typical of Eulima sensu stricto, with an elongated, conical shell of slowly increasing diameter, flat whorls, narrow and elongated aperture as the type species of the genus, E. glabra (da Costa, 1778) (Warén 1989).

MolluscaBase Eds. (2020a) cited Eulima rectiuscula Dall, 1890, from Georgia, USA, as a junior synonym of E. ephamilla without discussion. The holotype of E. rectiuscula (Figure 5D, E), collected from the USFC stn. 2668 (vide original label), also has a broken protoconch, but the general outline and dimensions are indistinguishable from the holotype of E. ephamilla. When Dall (1890) described E. rectiuscula, he also referred to samples of this species from the Caloosahatchee, a Plio-Pleistocene formation in Florida (Allmon et al. 1996). These fossil specimens were later recognized as a distinct species described by Gardner & Aldrich (1919: 39, plate 2, figure 5), currently known as Eulima dalli. In addition to the differences pointed by Gardner & Aldrich (1919), we add that the outer lip of E. ephamilla is more retracted at the proximal area than that of E. dalli. Thus, we consider E. rectiuscula as a junior synonym of E. ephamilla and that E. dalli is a valid species known only from the Miocene and Pliocene (Olsson & Harbison 1953). Eulima ephamilla is known only from two localities distant from each other by more than 6,000 km.

The general shape of Eulima ephamilla resembles E. incolor Bouchet & Warén, 1986 (Figure 5F, G), from deep waters off Spain, and E. psila Watson, 1883 (Figure 6 A–M), from the western Atlantic. However, E. ephamilla can be distinguished from E. incolor by the relatively bigger shell (holotype of E. ephamilla, 10 whorls, SL= 8.5 mm vs. holotype MNHN-IM-2000-5660 of E. incolor, 11 whorls, SL= 6.6 mm) and by the more elongated shape of the aperture. The aperture of both species is oblong but the ratio AW/AL in E. ephamilla and E. incolor is very different (0.69 and 0.48, respectively). Eulima ephamilla differs from E. psila by the outline of the outer lip, which protrudes in the former (Figure 5B, E) and is straight in the later (Figure 6I).

Geographical distribution. USA: Florida (Dall 1890); Brazil: Pernambuco (Watson 1883).

Bathymetric distribution. From 538 m to 640 m (Watson 1883; Dall 1890).