Eostrobilops humicolus Pall-Gergely & Hunyadi

Pall-Gergely, Barna, Hunyadi, Andras & Asami, Takahiro, 2015, A new Chinese species of Eostrobilops Pilsbry, 1927 with a checklist of Eostrobilops and Enteroplax Gude, 1897 species (Gastropoda, Pulmonata, Strobilopsidae), ZooKeys 508, pp. 85-95 : 88-89

Taxon classification Animalia Pulmonata Strobilopsidae

Eostrobilops humicolus Pall-Gergely & Hunyadi sp. n.

Material.

China, Guangxi (广西), Hechi Shi (河池市), Tiane Xian (天峨県), Qimu Xiang (豈暮郷), road junction toward Lahaoyan (拉号岩), cliff overlooking a memorial, 600 m, 24°51.130'N, 107°11.670'E, leg. Hunyadi, 12.09.2013., HNHM 99419 (holotype, Figure 1 A–C), HNHM 99420 (paratype, Figure 1 D–E and 2), HA/5 paratypes.

Diagnosis.

A small Eostrobilops species with a strongly ribbed dorsal surface, an infraparietal lamella not reaching the callus, and long basal folds.

Description.

Shell small, light brown (only one shell in type material had original colour); trochiform, rather domed above, almost flat ventrally (umbilical side), periphery rounded, very slightly keeled, suture rather deep; 4.75 (n = 3) slowly expanding whorls, protoconch approximately 1.5 whorls; virtually smooth but with weak microscopic pits arranged in irregular radial lines; teleoconch irregularly ribbed; ribs strong dorsally, very weak ventrally (except for inside the umbilicus); spiral structure entirely lacking; umbilicus narrow; inner margin of the whorls exposed in umbilicus irregularly crenulated; aperture semilunar and oblique; peristome slightly thickened and slightly reflexed; parietal callus weak; parietal and infraparietal lamellae well-developed, although the infraparietal does not extend to the peristome; a low interparietal lamella deeply situated, not visible from aperture; three long basal folds and one short columellar lamella; basal folds visible in one specimen with a fresh, translucent shell only (Figs 1 D–E, 2). However, this specimen was broken and the fold length can only be estimated (ca. a minimum of a quarter whorl).

Differential diagnosis.

Both Eostrobilops hirasei and Eostrobilops nipponica are much larger than the new species, they have a more rounded body whorl, wider umbilicus, and weaker dorsal sculpture. Eostrobilops coreana is larger and flatter than Eostrobilops humicolus sp. n., has a weaker dorsal sculpture, both of its parietal lamellae extend to the peristome, and has a shorter basal folds. Eostrobilops kanjiokuboi is similar to Eostrobilops humicolus sp. n. by having a strongly ribbed dorsal surface and long basal folds, but differs in the larger size, wider umbilicus, and the serrated lamellae (not serrated in Eostrobilops humicolus sp. n.); the infraparietal lamella extends to the callus (not in Eostrobilops humicolus sp. n.), and has a long palatal fold, which is lacking in the new species. Eostrobilops diodontina is slightly larger (D = 2.88, H = 1.75 mm), has more elevated parietal and infraparietal lamellae, and both lamellae attain the peristome. Moreover, Eostrobilops diodontina has shorter basal folds. Eostrobilops infrequens has a more elevated spire than Eostrobilops humicolus sp. n., a stronger callus, a narrower umbilicus and shorter basal folds. The spire of Eostrobilops triptychus is higher, it has more angulate periphery, thicker peristome and shorter basal folds.

Measurements

(in mm): D = 2.3-2.4, H = 1.45-1.5 (n = 2).

Etymology.

From Latin ( ‘humicolus’ = soil-dwelling), in reference to the fact that this species was found in soil samples.

Ecology.

No living specimens have been found. The empty shells were collected from a soil sample. Eostrobilops humicolus sp. n. probably lives under stones and dead leaves on the soil.

Type locality.

China, Guangxi (广西), Hechi Shi (河池市), Tiane Xian (天峨県), Qimu Xiang (豈暮郷), road junction toward Lahaoyan (拉号岩), cliff overlooking a memorial, 600 m, 24°51.130'N, 107°11.670'E.

Distribution.

Known from the type locality only.