A note on Parastrophia asturiana De Folin, 1870 (Gastropoda Prosobranchia: Caecidae)

Parastrophia shells from the South West of France and the North coast of Spain are regarded to belong to the species P. asturiana De Folin, 1870. Identical specimens from the Mediterranean area are usually called P. folini Bucquoy, Dautzenberg & Dollfus, 1884. Although the authors of the latter name explicitly state “M. de Folin, à qui nous avons communiqué ce Parastrophia, n’a pas hésité à le reconnaître pour une espèce nouvelle” we definitely do not find any character in the shells which would allow separation into two different species. As the animals of both taxa are still unknown at present we regard P. folini as identical with P. asturiana. This view was apparently also held by Hidalgo (1917: 531). In the more recent work of Priolo (1956: 271) the only Parastrophia mentioned is P. folini for which the name Spirolidium Mediterraneum O.G. Costa, 1861, is used. From the discussion given by Priolo we find it at least doubtful whether it can be established that this name can be the valid one for this species as the name was apparently based on embryonic forms, i.e. the first coiled part of the shell. Priolo does not discuss the relationship between this species and P. asturiana. Evidently he regards P. asturiana as a separate species on the authority of Bucquoy, Dautzenberg & Dollfus (and De Folin as quoted by them). Nordsieck (1968: 66) and Parenzan (1970: 101) also mention one species only, viz. P. folini, and list it as exclusively Mediterranean.