The large musk shrew, Suncus murinus (Linnaeus), was first taken on Guam in May, 1953 by the author. This is the first record, to his knowledge, of the species from an oceanic island. It is probable that the shrew was introduced into Guam from the Philippines where it is common. Shrews could easily enter bales or crates of cargo materials on the docks or in warehouses at a Philippine port that were destined for Guam and in that manner be transported to the Island. Once the cargo was offladen in Guam, shrews could escape and reproduce, thus establishing the species. This theory gains support from the fact that the first specimens taken were captured in a warehouse situated near Apra Harbor. Investigations made shortly after the first shrews were found revealed that colonies existed at various places in the harbor area, but none was found...