Helix cerioi Bellini, 1900a: 39

Fasulo, Giuseppe, Duraccio, Sergio, Federico, Antonio & Crocetta, Fabio, 2019, The (almost) unknown Italian naturalist Raffaello Bellini (1874 - 1930): biography malacological publications, and status of his recent molluscan taxa, Zootaxa 4668 (3), pp. 343-369 : 357-358

Helix cerioi Bellini, 1900a: 39

Type locality: Capri Island (Naples, Italy) .

Original description: “animal parvus, antice rotundatus, postice acuminatus, colori atro-rubro. Testa subperforata, globosa-depressa, obscure carinata, fragilis, opaca, subvitrea, pellucide subfasciata, rubescens; anfractus 5 ½ convexiusculi; apertura lunaris; peristoma acutum, extus rufulim. Diam. maj. 6 mm.; min 5 mm.; ap. 4 mm.” [small animal, rounded anterior part, acuminate posterior part, dark red in colour. Shell with a narrow umbilicus, depressed-globose, slightly keeled, fragile, matte, near to vitreous, with a slight transparent band, reddish in colour; 5 ½ whorls, slightly convex; moon-shaped aperture; peristome sharp, reddish in its external part. Maximum diameter 6 mm; minimum 5 mm; aperture 4 mm].

Material examined: a bulk of shells, divided in two parts but holding a single label by Monterosato “ Hel. Cerioi juv. et Hyal. Blauneri juv. [now Oxychilus blauneri (Shuttleworth, 1843) ]—Di Capri” (MCCIC—drawer 21, n. 312), belongs to non-identifiable juveniles of terrestrial molluscs. They come from the same type locality of Helix cerioi Bellini, 1900a . According to the MCCIC inventory, additional material belonging to this taxon should have been found in drawer 19 (n. 285) and drawer 21 (n. 313), but these locations are empty. Also Petraccioli (2005) mentioned the presence of specimens preserved in MCCIC holding original labels handwritten by Bellini, but without listing the exact location. Seven shells labelled by Monterosato “ H. Cerioi , Bell.—Capri, loc. orig. [località originale = locus typicus]” (MCZR-M-2987) belong to the Monacha cantiana (Montagu, 1803) species complex ( Fig. 6A ).

Remarks: considered a junior synonym of Monacha gregaria (Rossmässler, 1839) by Sacchi (1955b) and Alzona (1971), and of Monacha cantiana (Montagu, 1803) by Petraccioli (2005). Monacha gregaria is now considered a Sicilian endemic ( Bodon et al. 1995; Welter-Schultes 2012), and in this line Petraccioli et al. (2006) excluded its presence in Capri. Monacha cantiana , as well as H. cerioi , were also considered originally uncommon in Capri Island by Bellini (1900a); Petraccioli et al. (2005, 2006) did not find it during recent samplings held in Capri Island, and only listed Monacha cartusiana (Müller, 1774) as present. Noteworthy, species-level taxonomy of the genus Monacha Fitzinger, 1833 , and particularly of the M. cantiana species complex, is still unresolved ( Welter-Schultes 2012; Neiber & Hausdorf 2017; Pieńkowska et al. 2018, 2019). Apart of that, the absence of type material and even figures in any paper published by Bellini, as well as the fact that the description originally offered by Bellini (1900a) is then at least partially in disagreement with that provided subsequently ( Bellini 1915), led to the conclusion that it is here considered a nomen dubium ( ICZN 2012: glossary).

Figures

FIGURE 6. A. Helix cerioi. Shells from Capri Island (Naples) and original label handwritten by Monterosato. MCZR-M-2987 (6.2×9.8 mm, 7.7×10.9 mm, 7.8×11.8 mm). B–D. Helix amalfitana. B. Original figures. C. Possible type material from Cava de’ Tirreni (Salerno) (8×16 mm, 9×16 mm). C, D. Original labels handwritten by an unidentified curator and Monterosato. MZF2—box 34, n. 17.