andyk's picture

Arion fasciatus agg.

Observed: 9th February 2011 By: andyk
London Natural History Society
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Arion fasciatus agg.
Arion fasciatus agg. (1)
Description:

Found under old cow pat.

Identifications
Species interactions

No interactions present.

Comments

Brian Cambridgeshire's picture

Classic Arion circumscriptus

Jon summarises the features very clearly. A confusion is caused by the three Carinarion species, circumscriptus, fasciatus and silvaticus, not having been separated till the 1960s, and the names 'fasciatus agg.' and 'circumscriptus agg.' have both been used for the trio together.

Although the yellow pigment in A. fasciatus is a good feature, when A. circumscriptus ages, especially if it lives into a second year, it often goes a bit yellowish; but the black speckles on the upper side remain diagnostic.