Trochoidea, BROWN, 1827

Hausdorf, Bernhard & Sauer, Jan, 2009, Revision of the Helicellinae of Crete (Gastropoda: Hygromiidae), Zoological Journal of the Linnean Society 157 (2), pp. 373-419 : 404-406

TROCHOIDEA BROWN, 1827

Trochoidea Brown, 1827 : text for pl. 41, figs 80, 81. Type species (by monotypy): Trochus terrestris Pennant, 1777 (= Helix elegans Gmelin, 1791 ).

Diagnosis: Trochoidea is characterized by a symmetrical dart apparatus consisting of two small accessory sacs, and usually four branched glandulae mucosae around the vagina, two strong longitudinal folds that surround each opening of the accessory sacs into the vagina at the inner side of the wall of the vagina, and fuse pairwise at their distal and proximal ends, and a large rounded appendix at the atrium. Concerning the homology of the two small sacs at the vagina, see Xerocrassa . The penis is innervated from the right cerebral ganglion.

TROCHOIDEA PYRAMIDATA ( DRAPARNAUD, 1805)

( FIGS 10D , 11A , 12A; TABLES 1, 14 AND 15)

Helix pyramidata Draparnaud, 1805: 80 , pl. 5, fig. 6. Locus typicus: ‘sur les plages de la Méditerranée’. Abbreviations: da, dart apparatus; epd, epiphallus distal of the insertion of the penial retractor; epp, epiphallus proximal of the insertion of the penial retractor; fl, flagellum; p, penis; vda, vagina up to the base of the dart apparatus; vgm, vagina up to the glandulae mucosae; vt, total length of the vagina.

Trochoidea pyramidata – Vardinoyannis, 1994: 85, 87, 129, map 43.

Diagnosis: Trochoidea pyramidata is characterized by the conical shell, with a more or less rounded body whorl, and a narrow umbilicus.

Shell ( Fig. 11A ; Table 1): Conical; with 4.5–7 convex whorls; teleoconch with irregular growth ridges or fine ribs; whitish, sometimes with brown bands that might break up into spots; body whorl rounded or with a slight blunt edge at the beginning; aperture elliptical; upper insertion of the peristome not or slightly descending; peristome sharp, not expanded, with a whitish internal rib; umbilicus narrow, not or hardly obscured by the columellar edge.

Genitalia ( Fig. 10D ; Tables 14 and 15): See diagnosis of the genus. A more detailed description of the genitalia has been given by Giusti et al. (1995).

Distribution ( Fig. 12A ): Mediterranean region. In the eastern Mediterranean region probably introduced by man.

Figures

Figure 10. Helicellinae from Crete: genitalia. Scale bar: 1 mm. A, Xerocrassa rhithymna sp. nov., Moni Arkadiou, 3 km towards Thronos (holotype; ZMH 51067). B, Xerocrassa siderensis (Maltzan, 1883), Vai Finikodasos (ZMH 29445). C, Xerocrassa subvariegata (Maltzan, 1883), Chania, towards Rethimnon, at branch towards Souda (ZMH 29318). D, Trochoidea pyramidata (Draparnaud, 1805), Ierapetra, 6 km towards Makrigialos (ZMH 36466). E, Xeropicta krynickii (Krynicki, 1833), Limni Kourna (ZMH 29778). F, Pseudoxerophila bathytera (Westerlund & Blanc, 1879), Sikologos, 2 km towards Mirtos (ZMH 29524).

Figure 11. Helicellinae from Crete: shells. A, Trochoidea pyramidata (Draparnaud, 1805), Ierapetra, 6 km towards Makrigialos (ZMH 36466). B, Xeropicta krynickii (Krynicki, 1833), Limni Kourna (ZMH 29778). C, Pseudoxerophila bathytera (Westerlund & Blanc, 1879), Hagioi Pantés [syntype of Helix bathytera Westerlund & Blanc; NMGW]. D, Pseudoxerophila bathytera (Westerlund & Blanc, 1879), Mount Jouchtas [syntype of Helix suspecta Westerlund; NMGW]. E, Pseudoxerophila bathytera (Westerlund & Blanc, 1879), Ierapetra (syntype of Helix hierapetrana Maltzan; ZMB 39561). F, Pseudoxerophila bathytera (Westerlund & Blanc, 1879), Moni Toplou [syntype of Helix sitiensis Maltzan; ZMB 39576]. Scale bar: 5 mm for A; 10 mm for D–F.

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).