Icelopagurus tuberculosus, a distinct new hermit crab species (Crustacea: Decapoda: Paguridae) from Japan

A new species of pagurid hermit crab of the genus Icelopagurus McLaughlin, I. tuberculosus, is described and illustrated. It is the second species in the genus and is distinct in having a large well-calcified, immovable plate that is partially fused with the shield's posterior and posterolateral margins, a transverse row of four prominent protuberances on the dorsal surface of the shield, a pair of similar protuberances on each anterolateral margin of the shield, and a somewhat reduced abdomen. The new species is compared with the only other congeneric species, I. crosnieri McLaughlin. Morphological similarities and differences of Icelopagurus with selected, specialized pagurid genera are discussed.