Xerotricha, MONTEROSATO, 1892

Hausdorf, Bernhard & Sauer, Jan, 2009, Revision of the Helicellinae of Crete (Gastropoda: Hygromiidae), Zoological Journal of the Linnean Society 157 (2), pp. 373-419 : 413

XEROTRICHA MONTEROSATO, 1892

Xerotricha Monterosato, 1892: 23 . Type species (by monotypy): Helix conspurcata Draparnaud, 1801 .

Diagnosis: Xerotricha is characterized by a symmetrical dart apparatus consisting of two large dart sacs, two small accessory sacs that are separated from the dart sacs by a laplet, and four branched glandulae mucosae around the vagina. In the interior of the dart apparatus there are two tongue-like structures that are fused on one side of the vagina. The dart is slightly arched and is circular at its base, with very narrow blades at the top. The inner structure of the genitalia has been described in detail by Hausdorf (1988) and Giusti & Manganelli (1989). The penis is innervated from the right cerebral ganglion. The shell is small (diameter less than 10 mm) and carries hairs (or hair scars).

XEROTRICHA APICINA ( LAMARCK, 1822)

( FIGS 12F , 13D , 14C; TABLE 1)

Helix apicina Lamarck, 1822: 93 . Locus typicus: ‘environs de Brives’, France.

Diagnosis: Xerotricha apicina is characterized by a small, depressed conical shell, with strongly convex whorls and short hairs or hair scars, and the lack of an internal rib in the aperture.

Shell ( Fig. 13D ; Table 1): Depressed conical; with 3.75–4.25 strongly convex whorls; teleoconch with irregular growth ridges and short hairs (or hair scars); whitish, with a spotted corneous pattern; body whorl rounded or shouldered at the beginning; aperture almost circular; upper insertion of the peristome not or slightly descending; peristome sharp, not expanded, without an internal rib; umbilicus moderately wide, slightly eccentric, not obscured by the columellar edge.

Genitalia ( Fig. 14C ): See diagnosis of the genus. A more detailed description of the genitalia has been given by Giusti & Manganelli (1989).

Distribution ( Fig. 12F ): Mediterranean region and Macaronesian Islands. The species probably originated in the western Mediterranean region, and might have been distributed in the eastern Mediterranean in historical times by man.

XEROTRICHA CONSPURCATA ( DRAPARNAUD, 1801)

( FIGS 12G , 13E , 14D; TABLE 1)

Helix conspurcata Draparnaud, 1801: 93 . Locus typicus: ‘F.M. (= France méridionale) Dans les jardins, sous les haies, dans les fentes des murs’, France.

Helix (Xerophila) cretica – Martens, 1889: 187 (partim, non L. Pfeiffer, 1841).

Helicella conspurcata – Vardinoyannis, 1994: 84, 88, 132, map 49.

Diagnosis: Xerotricha conspurcata is characterized by a small, strongly depressed conical shell with short hairs or hair scars, and the lack of an internal rib in the aperture. It differs from X. apicina in the more depressed, usually less whitish shell, with less convex whorls and a usually less eccentric, slightly narrower umbilicus, and a shorter penis (shorter than the distal epiphallus in X. conspurcata ; longer than the distal epiphallus in X. apicina ), and in the dart apparatus that is less strongly tapering proximally than that of X. apicina .

Shell ( Fig. 13E ; Table 1): Strongly depressed conical; with 4–4.25 convex whorls; teleoconch with irregular growth ridges and short hairs (or distinct hair scars); whitish, with a spotted corneous pattern; body whorl rounded or shouldered at the beginning; aperture slightly elliptical; upper insertion of the peristome not or slightly descending; peristome sharp, not expanded, without an internal rib; umbilicus moderately wide, almost concentrical, not obscured by the columellar edge.

Genitalia ( Fig. 14D ): See diagnosis of the genus and the species. A more detailed description of the genitalia has been given by Hausdorf (1988) and Giusti & Manganelli (1989).

Distribution ( Fig. 12G ): Mediterranean region and Macaronesian Islands. The species originated probably in the western Mediterranean region, and might have been distributed in the eastern Mediterranean in historical times by man. The distribution in Greece and Turkey has been summarized by Hausdorf (1990b).

Figures

Figure 12. Distribution of Helicellinae on Crete (UTM grid, 10-km squares): •, records for which vouchers have been checked; -, records from the literature. A, Trochoidea pyramidata (Draparnaud, 1805). B, Xeropicta krynickii (Krynicki, 1833). C, Pseudoxerophila bathytera (Westerlund & Blanc, 1879). D, Pseudoxerophila oertzeni (Maltzan, 1887). E, Xeromunda candiota (L. Pfeiffer, 1849). F, Xerotricha apicina (Lamarck, 1822). G, Xerotricha conspurcata (Draparnaud, 1801). H, Microxeromagna lowei (Potiez & Michaud, 1835). I, Cernuella (Cernuella) virgata (Da Costa, 1778).

Figure 13. Helicellinae from Crete: shells. A, Pseudoxerophila oertzeni (Maltzan, 1887), Omalos (syntype; ZMB 39570). B, Pseudoxerophila oertzeni (Maltzan, 1887), north-western side of Limni Kourna (RMNH). C, Xeromunda candiota (L. Pfeiffer, 1849), Mesohori (ZMH 29990). D, Xerotricha apicina (Lamarck, 1822), Limin Chersonisou (ZMH 36954). E, Xerotricha conspurcata (Draparnaud, 1801), Stalida (ZMH 36202). F, Microxeromagna lowei (Potiez & Michaud, 1835), Greece, Lakonia, Sgardelianika near Neapoli (ZMH 51215). Scale bar: 5 mm.

Figure 14. Helicellinae from Crete: genitalia. Scale bar: 1 mm. A, Pseudoxerophila oertzeni (Maltzan, 1887), Omalos (ZMH 29719). B, Xeromunda candiota (L. Pfeiffer, 1849), Drapanos, 4 km towards Kokkinio Chorio (ZMH 36255). C, Xerotricha apicina (Lamarck, 1822), Corsica, Cardo (from Giusti & Manganelli, 1989: fig. 4B). D, Xerotricha conspurcata (Draparnaud, 1801), Sardinia, Valletta Logulentu (from Giusti & Manganelli, 1989: fig. 2B). E, Microxeromagna lowei (Potiez & Michaud, 1835), Greece, Lakonia, Sgardelianika near Neapoli (from Hausdorf, 1990b: fig. 1). F, Cernuella (Cernuella) virgata (Da Costa, 1778), Roustika, 0.2 km towards Rethimnon (ZMH 36110).