Turbonilla mermeroglaphyra, S, Absalão, Ricardo Silva, Santos, Franklin Noel & Oliveira, Deusinete, 2003

S, Absalão, Ricardo Silva, Santos, Franklin Noel & Oliveira, Deusinete, 2003, Five new species of Turbonilla Risso, 1826 (Gastropoda, Heterobranchia, Pyramidellidae) found off the northeast coast of Brazil º­ 13 º, Zootaxa 235, pp. 1-11 : 7

Turbonilla mermeroglaphyra n. sp. ( Figs. 11­14 )

Description: Shell small, tall, subcylindrical; color whitish. Teleoconch whorls almost straight in profile, slightly telescopic. Suture oblique, straight, well­marked but not deep. Protoconch heterostrophic planispiral; diameter 180 m in holotype. Axial ribs broad, low, straight, orthocline, becoming obsolete toward last whorls; about 20 ribs present on last whorl of holotype; interspaces narrow, about a quarter as wide as ribs. Spiral sculpture absent. Base rounded, usually smooth, but may have evanescent axial ribs slightly projecting over it. Aperture pyriform. Columella obliquely concave, with obsolete fold hardly visible. Outer lip thin. No umbilical fissure.

Dimensions: Holotype with eight teleoconch whorls; height 2.4 mm; width 0.6 mm.

Type material: Holotype: MNRJ 9825; Paratypes: IBUFRJ 12704; UFPE 4442, MORG 41058. All paratypes from 06º58’06”S, 34º31’25”W, #8 REVIZEE, 270 m depth, Rv. “Natureza” coll., off Paraíba State, northeast coast of Brazil, 29/xi/2001.

Type locality: 10º38’01”S, 36º11’05”W, #2 REVIZEE, 255 m depth, Rv. “Natureza” coll., off Alagoas State, northeast coast of Brazil, 22/x/1999.

Distribution: Restricted to deep waters off northeastern Brazil.

Etymology: From mermerizo (Gr.) = to be in doubt; glaphyros (Gr.) = smooth; i.e., mermeroglaphyra refers to the imprecise expression of the axial ribs, sometimes present and distinct, sometimes smooth and almost invisible.

Remarks: Turbonilla mermeroglaphyra superficially resembles T. portoricana Dall & Simpson, 1901 in profile ( Dall & Simpson, 1901: pl. 53, fig.15; Warmke & Abbott, 1962: pl. 29, fig. i; Pimenta & Absalão in press: figs. 72­73 [holotype]). However, T. mermeroglaphyra is more slender and has a more telescopic shell than T. portoricana . Additionally, T. portoricana has spiral ornamentation, absent in T. mermeroglaphyra . The low, illdefined, sometimes evanescent ribs are also seen in T. krebsii (Mörch, 1835) ( De Jong & Coomans, 1988: pl. 20, fig. 668; Redfern, 2001: pl. 67, figs. 626a­c; Pimenta & Absalão in press, fig. 49 [syntype]), and T. nivea (Stimpson, 1851) ) ( Wharton, 1976: figs. 2­6; Pimenta & Absalão in press, fig. 86 [holotype]), but T. krebsii has a semi­pupoid shell profile, spiral ornamentation, and brownish color; T. nivea , on the other hand, has no spiral ornamentation, but has very convex whorls and a trigonal shell profile.

Figures

FIGURES 8 ­ 14. 8 ­ 10. Turbonilla kamayura n. sp., holotype (IBUFRJ 12701). 8: whole shell, length 4.0 mm; 9: base detail; 10: protoconch detail. Scale bar = 100 µm. 11 ­ 14. Turbonilla mermeroglaphyra n. sp., holotype (MNRJ 9825). 11: whole shell, length 2.4 mm; 13: base detail; 14: protoconch detail; 12: paratype (IBUFRJ 12704), whole shell, length 2.8 mm. Scale bar = 100 µm.