Limnus

Dictionary of Greek and Roman Geography

LIMNUS an island off the coast of Ireland, mentioned by Ptolemy (Ptol. 2.2), as lying to the east of Ireland, and being uninhabited. Pliny also mentions it (4.30). It is probably Lambay Island. However, the Monumenta Britannicanot only suggests for Limnos (Ptolemy's Limnus) the modern names of Lamabay, Lymen, and Ramsey, but they also distinguish it from Limnus(Pliny's Limno s) which they make Dalkey.
[R.G.L]