Diogenes patae n. sp., a new species of hermit crab (Decapoda, Anomura, Diogenidae) from American Samoa, is described and illustrated. It belongs to a small group in the genus, in which the antennal. peduncles are slender and shorter than the ocular peduncles and the antennal flagella lack paired long setae. The new species is easily distinguished by very dense setation only on the left cheliped and the left second and third pereopods, presence of strong spines on the lateral faces of the second pereopod carpi, and the dorsoventrally flattened body with the flat dorsal surface of the shield and the flat and very broad XI and XII sternites (second and third pereopods).
