Three new species of obligate wood boring bivalves of the genus Xylophaga are described from depths greater than 1000 m in the North Atlantic. Xylophaga ricei n.sp. occurred in wood panels deployed for c. 20 months on the seabed south of Madeira at a depth of 5000 m. X. anselli n.sp. and X. gagei n. sp. were discovered in wood fragments which had been heavily bored by Xyloredo ingolfia Turner, 1972, trawled from the Rockall Trough to the west of the British Isles.