A NEW SPECIES OF GROSSUANA (CAENOGASTROPODA: TRUNCATELLOIDEA: HYDROBIIDAE)

Paludina hohenackeri Küster, 1853 from Greece is a junior synonym of Radomaniola tritonum (Bourguignat, 1852) [Hydrobia]; Grossuana hohenackeri sensu auctorum is described as a new species. key worDs: Radomaniola tritonum, Paludina hohenackeri, Grossuana tembii, new species, species identification, Greece


MATERIAL AND METHODS
Whorls were counted according to GittenBerGer et al. (1970).Anatomical examination followed Boeters (1999).Shells, animals and their parts were drawn with LEICA M80 Drawing Mirror.Shell length and diameter were measured with a 5 mm measure plate (0.05 mm grading) at 40× magnification; measurements were rounded to the nearest 0.05 mm.Photographs of shells were taken with a LEICA R8 digital system.
Animal (Figs 9-16): Except for the white mantle skirt, mantle, head and body wall pigmented black.
Ten ctenidium filaments (n = 1♂); inside the mantle cavity the intestine runs to the anus only slightly curved.Except for a black spot, the penis is pigmentless; it can be simple (Falniowski et al. 2012: 30, fig. 8 G19) or provided with a bifurcated outgrowth (Figs 9-16; n = 1).The renal oviduct carries a proximal and distal receptaculum (RS1, RS2) plus bursa.The tube-like bursa is of such a length that its top extends clearly beyond the turn of the intestine in front of the stomach (n = 2).(Falniowski et al. 2012: 22, table 1;M9, M3, G5 and G19).Falniowski et al. (2012: 25-26) state that as "a general rule, the variability of the penis was continuous.There was not a discrete difference between either Radomaniola and Grossuana and the nominal species/subspecies studied".Our results show that within the population of G. tembii n. sp. at its type locality, the bifurcated outgrowth may be present or missing.
As regards the renal oviduct of the species of Radomaniola and of Grossuana, Falniowski et al. (2012: 30) found that "as in the case of the penis, there is a continuous variation in the shape and size of the bursa copulatrix as well as in the shape and size proportions of the receptacles".
We found that the bursa copulatrix of G. tembii n. sp.corresponded to the large tube-like bursa as described by raDoman (1983: 56, fig. 24) for G. serbica, the type species of the genus.

PALUDINA HOHENACKERI KÜSTER, 1853
küster (1853) obtained the material for his description from Charpentier.One of the labels in cHarPentier's collection reads: "208 [in red] On the other hand, it should not be excluded that Charpentier obtained his material of Küster's Paludina hohenackeri from Hohenacker, a Swiss like Charpentier.Hohenacker traded in herbarium material, possibly also shells.He had never been in Greece, but got material from Theodor von Heldreich who at that time lived in Athens (wörz in litt.05.12.2016 and 17.07.2017).From 1829 to 1842 Hohenacker was associated with the Esslinger Reiseverein [travelling union], Unio Itineraria.

Grossuana tembii n. sp.
The species' name refers to the type locality, the Thembi [Tembi] valley.
Etymology: der of aperture neither broadened nor thickened; maturity reflected by a closely spaced series of growth stripes; columellar border slightly broadened, closing umbilicus or leaving it slit-like open.