Erctella insolida ( Monterosato, 1892 )

Colomba, Stella, Gregorini, Armando, Liberto, Fabio, Reitano, Agatino, Giglio, Salvatore & Sparacio, Ignazio, 2011, Monographic revision of the endemic Helix mazzullii De Cristofori & Jan, 1832 complex from Sicily and re-introduction of the genus Erctella Monterosato, 1894 (Pulmonata, Stylommatophora, Helicidae), Zootaxa 3134, pp. 1-42 : 35-36

Erctella insolida ( Monterosato, 1892)

Figs. 18–20 , 23

Helix (Helicogena) aspersa var. insolida Monterosato 1892: 26 (Favignana?; Monte San Giuliano). Helix (Erctella) mazzullii forma insolida — Monterosato 1894: 168 -169 (Monte San Giuliano or Erice, near Trapani). Helix mazzulli — De Gregorio 1894: 7 (fossil, Levanzo island); Piperno 1997: 140 (fossil: Uzzo cave).? Helix sp. — Varga 1989: 77 ( insolida ?).

Helix mazzulli var. vitincola De Gregorio 1895: 193 (San Vito) .

Helix (Cryptomphalus) aspersa — Alzona 1971: 220 [partim].

Cornu aspersum — Bank 2009 [partim], (Sicily).

Cantareus mazzullii — Fiorentino et al. 2004: 89 (fossil: Levanzo island). Cornu mazzullii insolidum — Colomba et al. 2008: 90.

Erctella insolida — Liberto et al. 2010: 115–116, fig. 156.

Shell ( Figs. 18–20 ). Large for the genus; height 33–40 mm (mean 34 mm); maximum diameter 29–35 mm (mean 31.8 mm); aperture height 22–26 mm (mean 24 mm); aperture maximum diameter 23.5– 28 mm (mean 25 mm); more globose; brownish or greenish; spire less elevated; external surface with very thin growth lines; peristome thickened, simple or little reflected; aperture rounded.

Animal. Generally dark.

Genitalia ( Fig. 23 ). Diverticulum of bursa copulatrix approximately as long as duct of bursa copulatrix; two digitiform glands each of which is divided into 23–45 slender and branched digit-like appendices; vagina internally with 7–8 longitudinal pleats; penial flagellum as long as penis and epiphallus together; internal surface of proximal cavity of the distal penis with transversal pleats subdivided in 1–2 longitudinal and raised pleats, a very small true penial papilla and a small papilla on the internal wall.

Remarks. Erctella insolida was described by Monterosato (1892) as a variety of Helix (Helicogena) aspersa , with the locus typicus: “Favignana?” and Monte San Giuliano (Trapani province). The Sicilian naturalist himself later (1894) modified the position of the taxon and slightly re-defined its distribution area, reporting it as a variety of H. (Erctella) mazzullii from Monte San Giuliano or Erice (Favignana being definitely ruled out). Afterward he changed his mind again and considered insolida a valid species [ H. (Erctella) insolida ] distinct from other related species, particularly from H. aspersa (= Cornu aspersum ) ( Ryolo & Palazzi 2009).

Populations described by De Gregorio (1895) under the name vitincola (from San Vito Lo Capo, Trapani province) and those reported under insolida (from Monte Cofano) show minimal morphological differences and only a slight genetic divergence.

Figures

FIGURES 18 – 20. Erctella insolida samples from several sites of the Trapani province showing different morphotypes. Each shell shown in frontal (a) and dorsal (b) view. 18. San Vito lo Capo, Cala Mancina, height (H): 34 mm, maximum diameter (D): 30 mm. 19. Custonaci, Monte S. Giovanni, H: 37 mm, D: 34 mm. 20. San Vito lo Capo, Monte Passo del Lupo, H: 40 mm, D: 37 mm.

FIGURE 23. a. Erctella insolida from Monte Cofano, genitalia. b. Idem, internal structures shown. c. Erctella insolida from San Vito lo Capo, Genitalia, internal structures shown.