Rediscovery of Bostryx voithianus ( Pfeiffer , 1847 ) ( Gastropoda , Pulmonata ) in northern Chile , with notes on the type locality

Bostryx voithianus (Pfeiffer, 1847) is reported, for the first time since its description, from northern Chile. In the original description, a particular type locality was not given for this species, but to it was described as collected in Chile by Thomas Bridges for the Hugh Cuming collection. Herein, the type locality is assigned to the Chilean Coastal Range between the places Cuesta La Arena (28.5721° S) and Quebrada Honda (29.5952° S), northern Chile.


Introduction
Within the group of Bostryx species described from Chile, Bostryx voithianus (Pfeiffer, 1847) has a particular and rather complex story.This species was originally described as Bulimus voithianus Pfeiffer (1847: 114) based on specimens, collected by Thomas Bridges, in the Hugh Cuming collection, now in the Natural History Museum, London (NHMUK).
In June 1848 in his Conchologia Iconica, Reeve (1848-1850: pl.21 fig.131) described the same species, also based on material from the Cuming collection, as Bulimus meridionalis.Reeve points remarked that "It is a very singular species, which appears to have escaped the vigilant search of both Cuming and d'Orbigny.It is very unlike any other Chilean species".Afterwards, in December 1848 in the same publication, Reeve (1848-1850: pl. 56, fig. 370) illustrated and described B. meridionalis Pfeiffer, 1848, a South African species.Finally, in 1850 in the index to this volume of Conchologia Iconica, after recognizing that Bulimus meridionalis Reeve, 1848 had been previously described by Pfeiffer (1847), Reeve emended the name assigned to the specimen shown in plate 21, figure 131 to B. voithianus (Breure and Ablett 2014).
Hupé (1854) introduced a new name, Bulimus festhamelii Hupe, 1854, for B. meridionalis Reeve, 1848, also by considering that the specific epithet meridionalis had been previously used by Pfeiffer (1848) for the South African species mentioned earlier.
In this way, in a just few years, Bostryx voithianus was described with 3 different names.However, despite its hectic story, its type locality was never specified, and it was referred to just as "found in Chile".

Methods
In December 2014, the author made an expedition all along the coastal zone of the Coquimbo, Atacama, and Antofagasta regions (northern Chile, between 22.2° S NOTES ON GEOGRAPHIC DISTRIBUTION and 30.0°S) with the purpose of collecting specimens of land snails at their type localities.This expedition made it possible to obtain representative material of the various taxa described in the 19th century from northern Chile.Seven empty shells of Bostryx voithianus were collected in 2 of the localities visited (Table 1).Both places are situated in the Chilean Coastal Range and correspond to fog oasis locations or lomas formations (Fig. 1).The lomas formations are fog-watered vegetation patches, distributed along the coastal desert of Peru and northern Chile, for nearly 3500 km (Dillon 2005).
The studied material is deposited in the Collection of Malacology of the National Museum of Natural History, Santiago de Chile (MNHNCL) (Table 1).

New records. Table 1.
Bostryx voithianus seems to be a rare species, based on the few number of specimens found.These were collected among and under stones, in rocky areas near the coast (Figs 2-4), at altitudes between 180 and 280 m above sea level.
Bostryx voithianus is one of the most characteristic species of the non-marine Chilean malacofauna.Its unique characteristics makes it quite different from the other Bostryx species described for Chile and, therefore, clearly identifiable.
The present identification was made by comparing the collected specimens ( The diagnostics characteristics of this species are its fusiform shape, conic spire and acute apex, along with a particular ornamentation, consisting of obtuse scales formed by the intersection of axial wrinkles and spiral grooves (Fig. 6).These characteristics, combined with its dull-white color and the aperture interior stained with deep purple-red (Fig. 5), makes this species easily recognizable.
To the naked eye, the protoconch looks smooth; on magnification, it shows a very delicate microsculpture consisting of a faint but dense set of spiral striations, along with a set of weak axial wrinkles.The protoconch sculpture is easily lost in worn shells.

Discussion
The relevance of this research lies in the rediscovery, after 170 years, of one of the more characteristic species of Chilean land snails.In the literature, there are no other specimens mentioned other than those collected by Bridges.Therefore, the 4 specimens (1 lectotype and 3 paralectotypes, designated by Breure and Ablett 2014: 208; Cuming collection, NHMUK) are the only known specimens of this species so far.Pfeiffer (1847) described a mixed series of 38 species of land snails from the Cuming collection.Seven of the species described come from unknown localities, while the other 31 come from widely dispersed, unrelated locations such as Greece, Tahiti, Philippines, New Guinea, Mauritius, Madagascar, Cuba, Jamaica, Mexico, Colombia, Bolivia, Archipelago of Juan Fernández (Chile), and continental Chile.Within this group, there are 3 species collected by Thomas Bridges, 2 of them coming from Bolivia (Bulimus draparnaudi Pfeifer, 1847 and B. porphyrius Pfeiffer, 1847), and 1 from Chile (B.voithianus), the latest without a particular locality.The 2 Bolivian species could have been collected during the trip made by the naturalist to Bolivia during 1845 (Dall 1866: 236), but the Chilean species seems to have a previous origin.Before that, Pfeiffer (1843) had published the description of 7 species of land snails, also coming from the Cuming collection and collected by Thomas Bridges in northern Chile (Table 2).
Based on the type localities of the collected species, it is possible to infer that the route followed by Bridges corresponds to the coastal road between the ports of Coquimbo and Huasco.The same trail was travelled by Charles Darwin in 1835, some years before the expedition made by Bridges (Darwin 1846).If indeed Bridges took this road, he would have passed by the lower zone of Quebrada Honda, while Cuesta La Arena corresponds to one of the localities where Bridges collected 2 of the species described by Pfeiffer (1843).
According to Recommendation 76A.1.of the International Code of Zoological Nomenclature (ICZN 1999), concerning to "In ascertaining or clarifying a type local-ity…", and in particular with Recommendation 76A.1.4.that states that "as a last resort [to ascertain a type locality], and without prejudice to other clarification, localities within the known range of the taxon or from which specimens referred to the taxon had been taken", it is now proposed to assign the type locality of Bostryx voithianus to the Chilean Coastal Range between Cuesta La Arena and Quebrada Honda localities, northern Chile.
It is possible that Bostryx huascensis (Reeve, 1848), based on material collected by Thomas Bridges in Huasco, had also been collected along with B. voithianus and the other taxa listed in Table 2 during the same  expedition.Probably, this taxon was not previously described by other authors who usually worked with the Cuming collection, due to its similarity with B. albus (Sowerby, 1833), a species that also inhabits the zone of Huasco (Pilsbry 1895(Pilsbry -1896)).

Figure 1 .
Figure 1.Map of the northern part of Coquimbo Region and southern part of Atacama Region (northern Chile), showing the localities where Bostryx voithianus specimens were collected (Cuesta La Arena and Quebrada Honda).

Table 1 .
List of localities where the author found Bostryx voithianus specimens in December 2014.Geographic coordinates in WGS84 datum.