Amphidromus (Syndromus) haematostoma Möllendorff, 1898

Inkhavilay, Khamla, Sutcharit, Chirasak & Panha, Somsak, 2017, Taxonomic review of the tree snail genus Amphidromus Albers, 1850 (Pulmonata: Camaenidae) in Laos, with the description of two new species, European Journal of Taxonomy 330, pp. 1-40 : 34-35

Amphidromus (Syndromus) haematostoma Möllendorff, 1898

Figs 1, 13 O−R

Amphidromus haematostoma Möllendorff, 1898: 74–75 . Type locality: Boloven (Boloven Plateau, Champasak, Laos).

Amphidromus haematostoma var. viridis Möllendorff, 1898: 75 . Type locality: Boloven (Boloven Plateau, Champasak, Laos).

Amphidromus haematostoma var. varians Möllendorff, 1898: 75 . Type locality: Boloven (Boloven Plateau, Champasak, Laos).

Amphidromus haematostoma – Pilsbry 1900: 182–183. — Zilch 1953: 132. — Laidlaw & Solem 1961: 527, 625. — Richardson 1985: 19.

Amphidromus haematostoma var. viridis – Pilsbry 1900: 183. — Zilch 1953: 132, pl. 22, fig. 4. — Laidlaw & Solem 1961: 527, 670. — Richardson 1985: 19.

Amphidromus haematostoma var. varians – Pilsbry 1900: 183. — Zilch 1953: 132, pl. 22, fig. 5. — Laidlaw & Solem 1961: 527, 668. — Richardson 1985: 19.

Amphidromus (Syndromus) haematostomus – Lehmann & Maassen 2004: 20.

Material examined

Type material

The species description included two varieties, “var. A. viridis ” and “var. B. varians ”, but only one set of shell measurements was given in the original description, of the nominotypical variety. The specimen SMF 7559, labelled as “var. A. viridis ”, exactly matches the dimensions given in the original description. Therefore, we believe this implied that the specimens of “var. A. viridis ” pertain to the type series of A. haematostomus s.s. The specimen SMF 7559 ( Fig. 13O) was designated as the lectotype in Zilch (1953: 132, pl. 22, fig. 4), which is considered to be a valid lectotype designation of the species, and the other specimen from the same lot becomes the paralectotype SMF 5760 (1 shell; Fig. 13P).

The other specimens labeled as “var. B. varians ” are distinct variants and are, therefore, excluded from the type series of this nominal species ( ICZN 1999: Art. 72.4.1). The specimen SMF 7561 ( Fig. 13Q) was designated as the lectotype in Zilch (1953: 132, pl. 22, fig. 5), which is considered to be a valid lectotype designation of “var. B. varians ”. Another specimen from the same lot became the paralectotype, SMF 5762 (1 shell; Fig. 13R).

Other material

LAOS: 6 + 2 juveniles, Boloven Plateau, Pakxong District, Champasak ( RMNH 101050); two lots in W.J.M.Maassen Collection (8S)and (12 + 2juveniles); 1shell,Boloven,Annam ( NHMUK 1899.4.22.74); 15 shells ( ZMB, ex. Lehmann Collection), 5 + 1 juvenile ( ZMB, ex. Lehmann Collection), in coffee plantation, near Pakxong, Boloven Plateau, Champasak.

Remarks

This species is currently known from the type locality only. The shell characters are clearly distinct from all other recognized species. The shell is sinistral and ovate conical. Then apex is acute, with a black spot on the tip. The last whorl is rounded; the color of the shell is a monochrome greenish (faded in old specimen), and there are a yellowish subsutural band and an umbilical area. Then aperture is ovate; the peristome expanded and weakly reflected; the lip is reddish-purple. The parietal callus is reddish-purple and thickened; the columella is also reddish-purple and dilated; the umbilicus imperforated.

Laidlaw & Solem (1961) suggested that this species was probably a junior synonym of A. roseolabiatus . However, after comparing the type specimens of both species and recently collected specimens of A. roseolabiatus , A. haematostoma clearly differs from it in having an ovate conical shape, uniform greenish to yellowish shell, yellowish subsutural and umbilical area, thickened parietal callus, lip widely expanded, and reddish-purple lip and parietal callus. Moreover, A. roseolabiatus exhibits an elongate conical shell, greenish radial streaks, white subsutural band, transparent parietal callus, and lip pinkish or white and expanded.

Lehmann & Maassen (2004: 20) recorded the genital characters (without illustration) of the topotypic population and mentioned that it had a “very short flagellum and a short conical verge”. These are the distinguishing characters of this subgenus. However, further investigation of the genitalia is necessary to confirm the subgeneric status.