Parthenina cf. interspatiosa ( Linden & Eikenboom, 1992 )

Pimenta, Alexandre Dias, Absalão, Ricardo Silva & Miyaji, Cintia, 2009, A taxonomic review of the genera Boonea, Chrysallida, Parthenina, Ivara, Fargoa, Mumiola, Odostomella and Trabecula (Gastropoda, Pyramidellidae, Odostomiinae) from Brazil, Zootaxa 2049, pp. 39-66 : 53

Parthenina cf. interspatiosa ( Linden & Eikenboom, 1992)

( Figs 31−35 )

Material examined: --southeast and south of Brazil: -- PADCT expedition: MZSP 89117, sta 6571 [9]; -- REVIZEE expedition: MZSP 89118, sta 6669 [4]; MZSP 89119, sta 6669 [1]; MZSP 89120, sta 6668 [2]; MNRJ 10965, sta 6656 [2]; MNRJ 10961, sta 6662 [2]; MNRJ 10885, sta 6668 [1].

Remarks: Parthenina cf. interspatiosa ( Figs. 31–35 ) is quite distinct from any other named western Atlantic pyramidellid species; the most similar is Egila sp. indet. A, published in Odé (1993c: 30), but the drawing provided in that work does not allow a comparison. However, there are some eastern Atlantic (European and African) species that have the same general shape and sculpture pattern found in P. cf. interspatiosa ; as discussed above, some of them were included in Chrysallida sensu lato (e.g. Peñas and Rolán, 1998) or in Chrysallida (Parthenina) (e.g. Aartsen et al., 2000) Among those, the most similar are Parthenina interspatiosa ( Linden & Eikenboom, 1992: 21, fig. 10, 25–26), and Parthenina pyttelilla ( Schander, 1994: 25, fig. 3a); both were included in Chrysallida . Especially in P. interspatiosa , the sinuous axial ribs, their spacing, the small apical swelling on the ribs below the sutures, the ornamentation on the base, and columellar fold are quite similar. The only minor difference is the umbilicus, which is absent in the European species but variably present in the Brazilian specimens of P. cf. interspatiosa ( Figs. 31−32 ). However, this is not unusual among pyramidellids; similar variation in umbilicus expression can be found in Eulimastoma canaliculatum ( Pimenta & Absalão, 2004b). Parthenina pyttelilla is slightly different, having less sinuous ribs, less prominent swelling on the ribs below the sutures, and a less ornamented base.

For the reasons mentioned in the introduction (geographic distribution section), we refrain from describing this material as a new species, but do not determine it categorically as Parthenina interspatiosa ; rather we refer to it provisionally as Parthenina cf. interspatiosa .

Parthenina cf. interspatiosa is restricted to localities in southeast coast of Brazil.

Figures

FIGURES 31 − 35. Parthenina cf. interspatiosa: 31, 35 − 35 (MZSP 89119); 32 (MNRJ 10885); 33 − 34 (MZSP 89118). 31 − 33: whole shells (respective lengths: 31: 1.5 mm; 32: 1.6 mm; 33: 1.9 mm); 34 − 25: protoconchs. Scale bars: 100 Μm.