Helix LINNAEUS, 1758

Neubert, Eike, 2014, Revision of Helix LINNAEUS, 1758 in its eastern Mediterranean distribution area, and reassignment of Helix godetiana KOBELT, 1878 to Maltzanella HESSE, 1917 (Gastropoda, Pulmonata, Helicidae), Contributions to Natural History 26, pp. 1-200 : 5-7

Helix LINNAEUS, 1758

1758 Helix LINNAEUS , Systema naturae, 10. edition, 1: 768 [type species: Helix pomatia LINNAEUS, 1758 ] [placed on the Official List by ICZN Opinion 94, 1926].

1778 Cochlea DA COSTA, Historia Naturalis Testaceorum Britanniae: 67 [type species: Helix pomatia LINNAEUS, 1758 ].

1820 Glischrus STUDER, Systematisches Verzeichniss Schweizer-Conchylien 11 [type species: Helix pomatia LINNAEUS, 1758 ]

1822 Helicogena FÉRUSSAC, Tabl. syst.: 23 [27], 27 [31] [type species: Helix pomatia LINNAEUS, 1758 ].

1831 Pomatia LEACH in Turton, A manual of the land and fresh-water shells of the British Islands: 45 [nomen nudum, as the type species ( Pomatia antiquorum TURTON, 1831) is also a nomen nudum].

1837 Pomatia BECK, Index molluscorum praesentis aevi musei principis augustissimi Christiani Frederici 1: 43 [type species: Helix pomatia LINNAEUS, 1758 ] [Preoccupied by Pomatia RÖDING, 1798 ].

1838 Coenatoria HELD, Isis (Oken) 1837 (12): 910 [type species: Helix pomatia LINNAEUS, 1758 ].

1882 Callunea MEGERLE in Scudder, Nomenclator Zoologicus, Suppl. List 56 [not available: published in nomenclator].

1882 Megastoma MEGERLE in Scudder, Nomenclator Zoologicus, Suppl. List 204 [not available: published in nomenclator].

1903 Pomatiana FAGOT , Bulletin de la Société des Sciences Historiques et Naturelles de la Corse 22: 241 [type species: Helix pomatia LINNAEUS, 1758 ].

1909 Pomatiella PALLARY, Mémoires présentés a l’Institut d’Égypte 6 (1): 21, 23 [non CLESSIN, 1889 = Cochlostomatidae ] [no type species selected].

1914 Physospira C. BOETTGER, Nachrichtsblatt der deutschen Malakozoologischen Gesellschaft 46 (3): 103 [type species: Helix vulgaris ROSSMÄSSLER, 1839 = Helix albescens ROSSMÄSSLER, 1839 ].

1918 Pachyphallus HESSE, Nachrichtsblatt der deutschen Malakozoologischen Gesellschaft 50 (1): 38 [type species: Helix ligata O.F. Müller, 1774 ].

1918 Rhododerma HESSE, Nachrichtsblatt der deutschen Malakozoologischen Gesellschaft 50 (1): 38 [type species: Helix asemnis BOURGUIGNAT, 1860 ].

1936 Cunula PALLARY , Journal de Conchyliologie 80 (1): 47 [nomen novum pro Pomatiella PALLARY, 1939 (non CLESSIN, 1889)].

1939 Tammouzia PALLARY, Mémoires présentés a l’Institut d’Égypte 39: 22 [type species Helix cincta var. anctostoma V. MARTENS, 1874 ].

Description

Shells almost always globular, columella brownish-blackish or white, variable colour banding pattern from five colour spirals to fused (usually in a sub and supraperipheral band), shell smooth or with a dense granulation on the upper whorls of teleoconch; diverticulum transformed to a thick, short tube never exceeding the bursa copulatrix in length, or reduced to completely lacking, both papilla with central perforation, mrp always attaching in a central position on the epiphallus, epiphallus as long as or considerably longer than penis.

To facilitate the understanding of the argumentation, the definitions of the subgenera of Helix are here translated and partly discussed.

Helicogena sensu Hesse (1908: 139) includes species with "a relatively short penis, the proximal part (epiphallus sensu Hesse)] very short, less than one third of the complete length; the flagellum is considerably longer than the penis. The diverticulum is shorter than the stem of the bursa copulatrix or completely lacking". This subgenus forms part of the genus Helix proper.

Physospira was created by C.R. Boettger because of the very broad protoconch of Helix albescens . Later, Hesse (1915–1920) justified Physospira anatomically as having a short and thick penis, a short flagellum, and the lack of the diverticulum. During the anatomical work it could be observed that 1) usually presence or absence of the diverticulum is a reliable character for species recognition, but 2) individuals may occur which should have a diverticulum but lack it, and vice versa. For this reason, the lack or presence of the diverticulum has to be considered very carefully in phylogenetic reconstructions. The "broad protoconch" is shared by several species ( salomonica , philibinensis ), which differ in their genital anatomy to a great extent. Thus, the name Physospira creates a paraphyletic group of species and has to be rejected.

Pachyphallus describes species with "a usually cylindrical, quite thick penis; the diverticulum is lacking or short, the flagellum is long, formed like a whip or short, formed like an awl". This description is inhomogeneous (short or lacking diverticulum) or uses characters, which can't be delimited (cylindrical and thick penis). It is based on the Italian species Helix ligata . The morphology of the genital organs in this species conform to the definition of Helix s. str. as used here (i. e. the diverticulum is reduced to a short tubule, and epiphallus is shorter than penis). Consequently, Pachyphallus is here considered a synonym of Helix (Helix) .

Rhododerma is defined as a Helix with a "fusiform penis, the pedunculus with a regularly present diverticulum; the animal is pink or fleshy coloured, a cervical crest is missing". In fact, living animals of H. asemnis can be red, but the structure of the genital organs does not significantly differ from that of Helix proper.

Tammouzia is created for anctostoma because this species often has a callosity on the columella. This character state varies considerably, and can also be found as an individual variation of H. asemnis . Since toothed columellae occur elsewhere within the Helicini , this character state is considered plesiomorphic, and the genus Tammouzia is rejected.

Remark: The main feature in Helix is the obvious transformation of the diverticulum. In other genera of the Helicinae , this organ is a very long and simple tube exceeding the vesicle of the bursa copulatrix in length. In Helix , however, the diverticulum does not exceed the vesicle, and is either very short and translucent to completely lacking, or is transformed to a short, flat and broad organ. While in H. ( Pelasga ) all species known anatomically have the latter form of diverticulum, in Helix (s. str.) both forms may occur. Reduction to complete loss of the diverticulum means that its function is superfluous, while in the other case the function may have changed. A comparative histological survey of this organ could shed some light on the problem.