Bythiospeum demattiai n. sp.

(Fig. 4­6)

Type series. Holotype (ZMH 79882): Shell height 1.7 mm, shell width 0.9 mm; Montenegro, Podgorica, spring in village Pričelje, 39 m a.s.l., 20.iv.­25.v.2014 Pešić . Paratypes (ZMH 79883): 9 shells.; 6 shells. coll. Glöer, same data and locality as holotype .

Locus typicus. Montenegro, Pogorica, spring Iverak in village Pričelje, 42°30'17.52''N, 19°13'17.93''E .

Etymology. Named after Willy De Mattia (Trieste) in appreciation of his contribution to the taxonomy of the molluscs.

Description

Shell: Shell elongated cylindrical with a large and obtuse apex (Figs. 4­6). The regularly growing 4.5 whorls are convex with a deep suture. Shell surface smooth. The aperture is ovoid, the outer margin is straight from lateral view (Fig. 6). The umbilicus is closed. The shell height 1.3­1.7 mm, shell width 0.7 mm, apertural/shell height ratio 0.3.

Soft body: unknown.

Differentiating features. The specimens from the Iverak spring are tentaively ascertained to the genus Bythiospeum Bourguignat, 1882 . However, considering that most of the numerous nominal species of Bythiospeum recorded from Europe are known as empty shells (Haase 1995) only one could expect that phylogenetic relationships within this group (including Paladilhiopsis Pavlović, 1913 as well) may be complex, and the genus is polyphyletic (Falniowski et al. 2014). Recently we described a new species of Bythiospeum Bourguignat, 1882 based on empty shells from Taban spring, situted only a few kilometres from the type locality of the new “ Bythiospeum “ species. Later on, we collected live specimens (Pešić and Glöer 2013), and ascribed B. bogici to a new distinct genus Montenegrospeum Pešić & Glöer, 2013, confirmed by molecular analysis (Falniowski et al. 2014). Montengrospeum bogici (Pešić & Glöer 2012) can easily be distinguished by the large dimensions of the shell (2.3 mm vs. 1.7 mm in B. demattiai) and having the circular, not ovoid, aperture. The shell of the new species resembles those of Devetakia Georgiev & Glöer, 2011 but the body whorl in the species of the latter genus known only from Bulgaria is more protruded (Georgiev and Glöer 2011).

Distribution. Montenegro; known only from the type locality.