Fossil marine diatom resting spore species in the morpho-genus Xanthiopyxis Ehrenberg are described using samples from DSDP Site 338 in the Norwegian Sea, Sites 436 and 438 in the northwest Pacific and from the onland section at Newport Beach, California. Xanthiopyxis is characterized by numerous knobs, spines and bristles covering the entire valve face. In this paper eleven species, of which seven are new species, are described and their stratigraphic ranges are presented: X. polaris Gran, X. norwegica Suto, sp. nov., X. brevispinosa Suto, sp. nov., X. teneropunctata Suto, sp. nov., X. lanceolatus Suto, sp. nov., X. circulatus Suto, sp. nov., X. reticulata Suto, sp. nov., X. obesa Suto, sp. nov., X. hirsuta Hanna and Grant, X. oblonga Ehrenberg and X. globosa Ehrenberg. In addition, resting spores which lack sufficient characteristics to identify easily are assigned to three informal species: Xanthiopyxis type A (knobbly type), X. type B (short spiny type) and X. type C (long spiny type).