Cochlostoma (Clessiniella), Zallot, Groenenberg, De Mattia, Feher & Gittenberger, 2015

Zallot, Enrico, Mattia, Willy De, Fehér, Zoltán & Gittenberger, Edmund, 2021, Cochlostoma revised: the subgenus Clessiniella Zallot et al., 2015 (Caenogastropoda, Cochlostomatidae), European Journal of Taxonomy 762 (1), pp. 49-95 : 64-66

Subgenus Clessiniella Zallot, Groenenberg, De Mattia, Fehér & Gittenberger, 2015

Clessiniella Zallot, Groenenberg, De Mattia, Fehér & Gittenberger, 2015: 80 .

Type species

Pomatias maculatum var. villae Strobel, 1851 , by original designation.

Remarks

The classification follows MolluscaBase (2021) except for the subgeneric name. Contrary to ICZN Art. 10.4, Neglecta Wagner, 1897 is used in MolluscaBase as a senior synonym of Clessiniella . Wagner (1897: 6 [570]) introduced Neglecta as “Formenkreis Neglecta ”. It cannot be denied that the German term Formenkreis is “.. a term such as “superspecies””. As a consequence, according to the ICZN ruling, Neglecta “.. is not deemed to be a genus-group name” (ICZN Art. 10.4, see also Zallot et al. 2015). Strobel (1851) and De Betta & Martinati (1855) named this entity Pomatias maculatum var. Villae – but referring to Pomatias maculatus Draparnaud, 1805 (= Co. (Co.) septemspirale ).

Diagnosis of the subgenus

SHELL. Ribbed teleoconch with straight ribs, variable in strength and shape. The columellar lobe is curved backwards, covering the umbilicus. The teleoconch spots (if present) form 2 rows on the whorls (often, a 3 rd row of spots is visible on the body whorl): the upper one close to the suture with rectangular spots abapically elongated; the lower one roughly ⅓ up on the whorls ( Fig. 12 ). In some populations the 2 rows of spots merge and there is a continuous vertical darker band on the whorls. The protoconch is dull and robust with fine riblets starting after 1.2 whorls or more from the apex; it is transparent and fragile or the ribbing starts close to the apex in other subgenera.

FEMALE GENITALIA. There is an apical connection of the pedunculus to the bursa copulatrix, a long seminal receptacle (normally club-shaped), which runs parallel to the pedunculus. The junction of the uterus gland is situated close to the connection between the pedunculus and the distal oviduct. This

combination of characters in the female genitalia is most diagnostic to distinguish Clessiniella from the other subgenera.

MALE GENITALIA. Apart from its apical part, the penial spermiduct is tortuous. The body spermiduct is protruding (often almost detached from the body) more than in the other subgenera and either straight or more or less tortuous. The posterior side of the penis is wrinkled.

Identification key for the species

1. Body whorl inflated shortly before the lip ( Fig. 4A : OB). In the female genitalia, simplified loop path with 1–2 loops ............................................................................ Co. (Cl.) anomphale Boeckel, 1939

– Body whorl not inflated before the lip ( Fig. 4A : FF, AF, II) ............................................................. 2

2. In the female genitalia, the loops of the visceral oviduct are 1–2 ........ Co. (Cl.) stelucarum sp. nov.

– In the female genitalia, the loops of the visceral oviduct are more than 2 ....................................... 3

3. In the male genitalia, the body spermiduct is twisted ............... Co. (Cl.) waldemari ( Wagner, 1897)

– In the male genitalia, the body spermiduct is straight ...................................................................... 4

4. Ribs of the shell widely spaced and barely inclined, protoconch relatively small ( Fig. 13 ). Slim, club-shaped seminal receptacle in the female genitalia ..................... Co. (Cl.) villae ( Strobel, 1851)

– Ribs less widely spaced and more inclined, relatively larger protoconch. Less slim seminal receptacle .......................................................................... Co. (Cl.) tergestinum ( Westerlund, 1878)

Figures

Fig. 12. Most common spot patterns on the shells of the species of Clessiniella Zallot et al., 2015.

Fig. 4. Features of the shell of Clessiniella Zallot et al., 2015. A. Shape of the body whorl approaching the aperture. B. Strength of the spots on the shell (0 = spotless shell to 2 = really evident spots). C. Strength of the ribs (1 = weak ribs to 3 = really prominent ribs). D. Strength of the ribs on the external side of the body whorl approaching the aperture (W= smooth shell; I = intermediate; S = prominent ribs).

Fig. 13. Shell characters (ribs inclination and relative size of the protoconch) which could be helpful to distinguish Cochlostoma (Clessiniella) villae (Strobel, 1851)(blue diamonds) fromCo. (Cl.) tergestinum (Westerlund, 1878) (green triangles).