Parastrophia avaricosa sp. n.

Figs 19A–C, 20, 25A

Etymology: The name is composed by the Greek α (not) and the Latin adjective varicosus (= provided with a varix) due to the absence of the varix between the uncoiled protoconch and the teleoconch that occurs in all the other Parastrophia species.

Description: Tube slightly bisinuous, very thin, vitreous, tapered. Coiled protoconch small, ovoid, of half a whorl. Uncoiled protoconch smooth, conical in the adapical half, then subcylindrical, curved and with a slight constriction before the transition to the teleoconch, which is marked by a simple scar. Teleoconch gently curved and slowly growing, characterized by the presence of a microsculpture composed by shallow, irregularly set grooves spaced about 5 µm apart. Aperture rounded, simple, without any feature. Length 1.5 mm. Operculum unknown.

Type locality: SOUTH AFRICA: Eastern Cape: Mzamba.

Holotype (Figs 19A–C, 25A): SOUTH AFRICA: Eastern Cape: sh, Mzamba, beach, leg. J.P. Marais vii.1976 (NMSA E1665 / T3354), length 1.47 mm, protoconch diam. 0.08 mm, max. diam. (apertural end) 0.26 mm .

Paratypes: MADAGASCAR: 9 sh, E of Cap Antsirabe, 25°02.8–03.0'S 47°01.3–02.0'E, sable vaso-sableux compact, - 49–52 m, 6.v.2010 (MNHN-IM- 2012 - 2726); 1 sh, Phare Flacourt, 25°01.3'S, 47°00.5'E, fond rocheux avec dalle,- 18 m, 1.v.2010 (MNHN-IM- 2012 - 2727); 1 sh, SW of CapAndavaka,chalutier “NosyBe II”, - 53–54 m, 25°16.9'S, 46°31.3'E, 4.v.2010 (MNHN-IM- 2012 - 2728) .

Comparative material examined: P.cornucopiae de Folin, 1869, lectotype (MNHN-IM-2000-24917) selected by Pizzini et al. 2013 (2013: 43, fig. 16F, G); P. filum Melvill, 1906, holotype from Gulf of Oman, 156 fms (NHMUK 190610.23.47); P. japonica Hinoide & Habe, 1978, holotype (NSMT-Mo 55474); P. melanesiana Pizzini, Raines & Vannozzi, 2013, holotype (MNHN-IM-2000-24882).

Distribution: This species is known only from the eastern coast of South Africa (type locality, Fig. 20) and from the southern coast of Madagascar around Talanaro.

Remarks: Parastrophia avaricosa sp. n. is the only known Parastrophia species without a separation varix between protoconch and teleoconch, thus it is immediately distinguished from all the other congeners. The new species resembles P. cornucopiae de Folin, 1869, P. japonica Hinoide & Habe, 1978 and P. melanesiana Pizzini, Raines & Vannozzi, 2013 (all figured in Pizzini et al. 2013) due to the paucispiral protoconch. Parastrophia cornucopiae is similar to P. avaricosa, having in common a similar shape of the protoconch, but the latter completely lacks the varix separating the uncoiled protoconch from teleoconch. Moreover, Parastrophia avaricosa shows a microsculpture composed by fine collabral grooves that is not observed in P. cornucopiae . Parastrophia avaricosa is also similar to P. japonica and P. melanesiana, but the latter two show a distinct separation varix and a longitudinal microsculpture (Pizzini et al. 2013).