« On my submitting this species and the following (which I could not find described) to Mr. Alder’s opinion, he believed them to be new, and before returning the specimens, wrote descriptions and made drawings of them for his own guidance. Having offered to copy these for my use if desired, I gladly availed myself of the proffered kindness, feeling well-satisfied that the descriptions would be better than any drawn up by myself, and that the figures would be most faithful. — Rissoa Warreni. – “Shell slender, tapering, thin, transparent yellowish white, with six much rounded and deeply divided whorls terminating in a rather fine point, the nucleus sunk in the apex. Aperture oblong-oval; outer lip thin, without rib; inner lip not reflected, but having a deep umbilicus behind it. The shell is slightly wrinkled by the lines of growth, and is delicately striated spirally; the striae can only be seen with a good magnifier, and are most distinctly observable at the base. There are also some faint indications of small obsolete ribs on the middle whorls. […]” Two specimens were found at Portmarnock (Dublin coast) by T. W. Warren, Esq.  » – W. Thompson: “Additions to the fauna of Ireland”, Annals and Magazine of Natural History vol. XV, London 1845, p.315.