Stapafurdius costiferus, Simone, 2021

Simone, Luiz Ricardo L., 2021, Stapafurdius, a new genus of Bulimulidae (Mollusca, Eupulmonata) from Bahia, Brazil, with two new species, Papéis Avulsos de Zoologia (Pap. Avulsos Zool., S. Paulo) 61, pp. 1-7 : 2

Stapafurdius costiferus sp. nov.

( Figs. 13-23 , 27-29 ) http://zoobank.org/ 4AEDCA60-4A2A-4F04-9CC4-6517F1303B78

Types: Holotype MZSP 154046 ( Figs. 13-18, 21 ) . Paratypes MZSP 153882, 3 shells from type locality ( Figs. 19-20, 22-23 ).

Type locality: BRAZIL. Bahia: Andaraí, Ubiraitá, 12°35′23″S, 41°00′26″W [Wesley Vailant col., iii.2021] ( Fig. 30 ).

Etymology: The specific epithet means “bearing ribs” in Latin, an allusion to the shell axial sculpture.

Diagnosis: Shell rather cylindrical, sculpture strong axial cords.

Description

Shell: About 12 mm, elongated, slightly turriform; width ~ 30% of length. Spire angle initially ~ 25°, becoming almost cylindrical in two last whorls, i.e., growth increasing relatively uniformly in first 3-4 whorls, gradually becoming same-sized in two last whorls, except for peristome slightly dislocated externally. Color pale beige, with relatively wide, sparse, brown spots, of apparent random distribution ( Figs. 13-15, 22 ). Protoconch ( Figs. 18, 23 , 28, 29 ) of 2.5 whorls, width 1.1 mm; whorls relatively rounded, suture deep; sculpture delicate net of spiral and axial lines, equally predominating, uniform, easily eroded ( Fig. 18 ); ~ 30% of shell width, ~ 5% of shell length; transition with teleoconch relatively clear, prosocline, ~ 20° in relation of longitudinal axis ( Figs. 28, 29 ). Teleoconch of ~ 5 whorls, suture relatively shallow, but well-marked; transverse section rounded ( Fig. 17 ); peristome dislocated externally to right, from slightly ( Figs. 19-20 ) to well-dislocated ( Figs. 13, 15 ). Sculpture uniform axial cords, ~ 20 in penultimate whorl; each cord well-marked, from suture to suture (except for short region preceding superior suture) ( Fig. 27 ); cords interspaces equivalent to double of cords width; interspaces with aligned minute dots parallel to cords ( Figs. 21 , 28 ); in last whorl sculpture similar to other regions, contouring inferior last whorl region, fading inside umbilicus ( Figs. 13, 16, 20 ). Aperture antero-posteriorly elongated, width ~ 40% of length ( Figs. 13, 20 ); peristome slightly prosocline, ~ 10% in relation to longitudinal axis ( Fig. 14 ); outer lip straight in middle, curved in both ends; anteri- or edge rounded; inner lip relatively similar to outer lip, attached to last whorl only in its superior third, sometimes producing low callus ( Figs. 20 ), sometimes planar ( Fig. 13 ). Umbilicus opened ( Fig. 16 ), protected on right side by middle region of inner lip ( Figs. 13, 20 ). Immature specimen subuliniform ( Figs. 22 , 27 ).

Figures

Figure 30. Map of Brazil with states outlined. Bahia indicated by“BA”, with indication of places of occurrenceof Stapafurdius glaber sp.nov.(1 = Ituaçu) and of S.costierus sp.nov. (2 = Ubiraitá).

Figures 13-23. Stapafurdius costiferus sp. nov., shell of types. (13-17) Holotype MZSP 154046 (L 12.0 mm). (13) frontal view. (14) right view. (15) dorsal view. (16) inferior-slightly left view.(17) apical view.(18) protoconch and first teleoconch,profile, scale = 1 mm. (19-20) Paratype MZSP 153882#1 (L 11.1 mm): dorsal and frontal views.(21) holotype,detail of sculptureof penultimate whorl,scale = 1 mm.(22-23) paratype MZSP 153882#3 (L 9.8 mm). (22) frontal view.(23) protoconch and first teleoconch,profile,scale = 1 mm.

Figures 24-29.Stapafurdius gen. nov.young shell SEM images.(24) S.glabersp.nov.paratype MZSP 154047,whole dorsalview,scale = 1 mm.(25) same,detail of apical region,dorsal-slightlyapical view,scale = 500 µm.(26)same,detail of transition protoconch-teleoconch,scale = 100 µm.(27) S.costiferus sp. nov.paratype MZSP 153882,whole dorsal view,scale = 1 mm.(28) same,detail of apical region,dorsal-slightly apical view,scale = 500 µm.(29)same,detail of protoconch and first teleoconch whorl,scale = 200 µm.