Virpazaria Gittenberger 1969

Genus Virpazaria Gittenberger, 1969 Type species

Virpazaria adrianae Gittenberger, 1969, by original designation.

Shell discoid, dextral, ribbed, colourless (weathered specimens are opaque white), peristome attached, thickened, usually with knob- or tooth-like prominences on palatal and/or basal sides. Peristome insertions are connected; this parietal connection varies from a swollen bulge to a lamelliform flap; in some species this flap might cover a significant part of the aperture in frontal view. Aperture somewhat narrow and moon-shaped.

According to Gittenberger (1969, 1975) as well as Reischütz & Reischütz (2009), Virpazaria is distinguished from the conchologically similar genus Spelaeodiscus by the continuous peristome, i.e., the presence of a parietal bulge or flap that connects the peristome insertions. Spelaeodiscus virpazarioides Páll-Gergely & Fehér, 2018 also possesses a callous parietal structure, but it is much smaller in proportion to the size of the whole aperture. Also, the narrower, crescent-shaped aperture is a good feature to tell Virpazaria apart from related genera.

Due to their hidden life, in most of the cases only empty shells are found. So far, there is one reported case when Virpazaria, more specifically two individuals of V. deelemanorum, were found alive (Gittenberger 1975). Having no pigmented eyes, they are presumably blind, as is usual for subterranean animals. Comparing their genitals to those of Spelaeodiscus, Klemmia and Aspasita Westerlund, 1889 (Bole 1965; Hudec 1965; Gittenberger 1975; Subai & Dedov 2008), one might discover differences in terms of proportional lengths of certain reproductive organs, and there are certain structures that are called differently by different authors (e.g., the same short protrusion at the border of penis and epiphallus is referred to as flagellum by Gittenberger (1975) and penial caecum by Schileyko (1998)). However, the overall arrangement of the genitalia is similar in these four genera, and no genus-specific differences could be found on the basis of the available literature.

1. Two lamellae, one palatal and one basal, reach deeply (more than 1/10 of whorl) into the aperture............................................................................................. V. (Aemiliella) ripkeni Gittenberger, 1969

– No deeply reaching lamellae in the aperture, just knob(s) or on elongated thickening parallel with the peristome......................................................................................................................................2

2. In frontal view, the crescent-shaped hole of the aperture is well visible..........................................3

– In frontal view, the hole of the aperture is almost or entirely covered.............................................5

3. One knob and a basal thickening on the peristome........... V. (V.) gittenbergeri Fehér & Erőss sp. nov.

– Two knobs on the peristome...............................................................................................................4

4. Shell width greater than 5 mm................................................... V. (V.) pesici Fehér & Deli sp. nov.

– Shell width less than 5 mm................................................ V. (V.) deelemanorum Gittenberger, 1969

5. Upper side of the shell is entirely flat in frontal view........ V. (V.) stojaspali Reischütz et al., 2009

– Shell is conical in frontal view...........................................................................................................6

6. No knobs on the peristome................................................................................................................7

– At least one knob on the peristome..................................................................................................8

7. Very narrow umbilicus..... V. (V.) aspectulabeatidis Reischütz et al. in Reischütz & Reischütz, 2009

– Wide, perspectivical umbilicus....................................................... V. (V.) pageti Gittenberger, 1969

8. Less than three knobs on the peristome............................................................................................9

– Three knobs on the peristome..........................................................................................................10

9. An elongated basal thickening and a detached palatal knob on the peristome................................................................................................................................. V. (V.) backhuysi Gittenberger, 1969

– Palatal knob is fused to the basal thickening of the peristome............................................................................................................................................... V. (V.) gittenbergeri Fehér & Erőss sp. nov.

10. In bottom-view the umbilicus seems wider than ¼ of the shell width, in frontal view the shell is flat conical (H:W <2:3)........................................ V. (V.) adrianae Gittenberger, 1969

– In bottom-view the umbilicus seems narrower than ¼ of the shell width, in frontal view the shell is conical (H:W ≈ 2:3)................................... V. (V.) nicoleae Reischütz & Reischütz, 2012