A battalion of the US 36th Division lost 508 casualties in one day (13th Sept 1943) forcing it to retire over the Calore river, whilst fighting a desperate battle to protect the Salerno bridgehead during the early days of the Italian campaign of WW11.
516 - 516 Amherstia was the 8th asteroid discovered by Raymond Smith Dugan, and was named after Amherst College, his alma mater. Amherstia is a large M-type asteroid, with an estimated diameter of 73 km. It follows an eccentric orbit between Jupiter and Mars, with an orbital period of 4.39 years.
518 - Coleophora mayrella (no 518 on the list of UK moths) is a widely distributed species throughout Britain and Ireland that frequents grassy areas and waste ground - I expect it can be found around the St Mary's area of Southampton then.