On Helix grisea Linnaeus, 1758 and the Helix species described by Carl Linnaeus and Otto Friedrich Müller

Helix grisea was described by Linnaeus in 1758, and its identity has been doubtful ever since. The name features
in the early taxonomic history of some other species of Helix sensu lato. Here I provide a summary of the history
of its use. Mostly, the name was applied for the widespread species now accepted as Cornu aspersum (O. F.
Müller, 1774), while a few authors used it for Helix cincta O. F. Müller, 1774. Neither usage is in line with the
Linnaeus' account. Based on a figure to which Linnaeus referred, I propose that the name originally applied to
a species now known as Helix lucorum Linnaeus, 1758 and as the first reviser, I give precedence to H. lucorum
over H. grisea. In respect to C. aspersum, H. grisea cannot take precedence because of reversal of precedence
according to Art. 23.9, and is pronounced a nomen oblitum. The case of H. grisea illustrates the importance of
Müller's work for the taxonomy of the genus. In this respect it is regrettable that some of his species, including
C. aspersum, lack a known and well documented type specimens.