Aclis macrostoma Barros, Lima & Francisco, 2007

Aclis macrostoma Barros, Lima & Francisco, 2007: 62, Fig. 7–9: Rios (2009: 198, Fig. 490); Cavallari et al. (2016: 35).

Type material. Holotype: MZSP 77988; R/ V Natureza col., 26/xi/2001 . Paratypes: Brazil: Rio Grande do Norte: Revizee Nordeste; 04°51′00″S, 35°06′46″W, 375 m; 24/xi/2001; R/ V Natureza; MZSP 77989 [2]; Revizee Nordeste; 06°14′24″S, 34°52′06″W, 500 m; 26/xi/2001; R/ V Natureza; MZSP 77990 [1]: LMUFRPE 022 [1].

Type locality. Brazil: Rio Grande do Norte; Revizee Nordeste; 06°14′04″S, 34°52′33″W, 510 m.

Material examined. Only the holotype.

Measurements. Holotype, MZSP 77988: 3 whorls; SL= 1.08 mm; BWL= 0.80 mm; AL= 0.54 mm; SW= 0.74 mm; AW= 0.50 mm. Paratype LMUFRPE 022: 3 whorls; SL= 1.08 mm; BWL= 0.81 mm; AL= 0.54 mm; SW= 0.71 mm; AW= 0.50 mm.

Remarks. Aclis macrostoma is known only by the type series and has conspicuous characteristics among the taxa of the present study, such as the broad elliptical aperture, having about half the total size of the shell, and the outer lip vastly expanded in comparison to the other species (Barros et al. 2007: Figs. 1, 5). Although type specimens have a tiny size, the expanded aperture, well-formed inner lip and the relatively sizeable umbilical fissure indicate that this may represent an adult specimen.

Geographic Distribution. Brazil: Rio Grande do Norte (Barros et al. 2007). From 375 to 510 m.