Orthalicus bensoni (Reeve, 1849)

Breure, Abraham S. H. & Avila, Valentin Mogollon, 2016, Synopsis of Central Andean Orthalicoid land snails (Gastropoda, Stylommatophora), excluding Bulimulidae, ZooKeys 588, pp. 1-199 : 50

Taxon classification Animalia Stylommatophora Orthalicidae

Orthalicus bensoni (Reeve, 1849) Figs 48 A–E, 52

Bulimus bensoni Reeve 1849 [1848-1850]: pl. 78 fig. 571; Breure and Ablett 2015: 23, figs 12 i–ii, L2ii [not 11 v–vii].

Orthalicus isabellinus Martens 1873: 190, pl. 1 fig. 8; Breure 2013: 23, fig. 22 G–H, 22iv.

Orthalicus bensoni ; Richardson 1995: 98 (references); Ramírez et al. 2003: 282; Simone 2006: 156, fig. 530; Breure and Borrero 2008: 26; Massemin et al. 2009: 406, pl. 5E; Linares and Vera 2012: 151.

Type locality.

"Banks of the Amazon".

Type material.

NHMUK 1975582 (1), syntype.

Additional material.

ZMB 8876 (2), syntypes of Orthalicus isabellinus Martens.

Diagnosis.

Shell sculptured with dense spiral lines, colour pattern predominantly with three small spiral bands of dark reddish-brown interrupted with white << marks, aperture with a small dark band behind the lip, around the columellar margin, and on the parietal wall.

Dimensions.

Shell height 66.6, diameter 35.0 mm.

Distribution.

Colombia. Ecuador, Prov. Napo, Sarayacu ( Pilsbry 1899: 148); Río Napo (CMC C10806). Peru, no specific locality ( Martens 1873). Brazil ( Simone 2006). French Guiana ( Massemin et al. 2009). Suriname ( Altena 1975).

Ecoregion.

Eastern Cordillera real montane forests [NT0121].

Remarks.

The figures by Breure and Ablett 2015: figs 11 v–vii are not of the syntype; this error is corrected herein. This species seems only slightly different from the Colombian Orthalicus bifulguratus (Reeve, 1849). The Peruvian record is based on the specimens described by Martens as Orthalicus isabellinus , which were collected by Tschudi at an unspecified locality (Breure 2013). Strebel (1909: 29) remarked that these subadult shells were not quite typical; however, we are of the opinion that Martens’ and Reeve’s taxa may be synonymous, although some doubt remains. The species is evidently widely distributed within the Amazon river basin, although molecular research may show that the Peruvian population is distinct from the eastern forms; in that case Martens’ taxon should be resurrected.