Graham, A. (1988) Molluscs: prosobranch and pyramidellid gastropods. In Kermack, D.M. & Barnes, R.S.K. (Eds.) Synopsis of the British Fauna (New Series). No. 2 (Second Edition). E.J. Brill/Dr. W. Backhuys for the Linnean Society of London and the Estuarin (look up in IMIS) [details]
by one year the animals have a shell heigh of 8-10 mm, at 2 years 13-16 mm, 3 years 15.5+ mm