AGARDHIELLIDAE HARL & PÁLL-GERGELY, 2017

FAMILY AGARDHIELLIDAE HARL & PÁLL-GERGELY View in CoL FAM. NOV.

Type genus: Agardhiella Hesse, 1923, type species: Pupa truncatella Pfeiffer, 1841, by original designation .

Included genera: Agardhiella Hesse, 1923 and Enneopupa Boettger, 1889 (fossil).

Diagnosis: Shell dextral, cylindrical; peristome moderately thickened and expanded; protoconch finely granulated; teleoconch ribbed; aperture with angular, parietal, palatal, infraparietal, columellar, infracolumellar and basal folds and/or palatal, parietal and basal ridges; penial caecum (swelling on the penis) present; epiphallar caecum might be present; penial appendix rather short; stalk of bursa copulatrix short; diverticulum absent. The diagnosis of Agardhiellidae fam. nov. agrees with that of the genus Agardhiella (see Schileyko, 1998; Subai, 2008, 2011).

Distribution: Southern and Eastern Europe (Balkan Peninsula, Alps, Southern and Eastern Carpathians, Transylvania).

Remarks: The nomenclatural background of the genus Agardhiella Hesse, 1923 (previously Agardhia Gude, 1911 ) and Argna Cossmann, 1889 [previously Coryna Westerlund, 1887 and Rhytidochasma A. J. Wagner, 1914 (in Sturany & Wagner, 1915)] is complex and is not discussed here in detail. Agardhiella Hesse, 1923 has been treated as a subgenus of Argna , until Gittenberger (1974), based on anatomical data, elevated it to generic level. Consequently, although not mentioned by Hudec (1965), Agardhiella was placed into Argnidae together with the genus Argna .

Agardhiella has so far been hypothesized to be closely related to the genus Argna because of the similar cylindrical shell. The present phylogeny, however, shows that the two genera (i.e. Argna and Agardhiella ) are not closely related and form distinct branches within the Orthurethra. Therefore, we propose a new family for the genus Agardhiella . Agardhiellidae fam. nov. differs from Argnidae by the shorter apertural folds, the shorter stalk of the bursa copulatrix (without diverticulum) and shorter penial appendix.

The fossil genus Enneopupa (Europe from Late Oligocene to Late Miocene)is placed withinAgardhiellidae because of the presence of two parietal lamellae, similar to some Agardhiella species. In contrast, members of Argnidae have a single parietal lamella.