A new species, Mursia longispina, previously confused with Mursia armata de Haan, 1837 and which is distinguished by the longest lateral spines of the carapace known in the genus Mursia, is described after specimens caught in New Caledonia.
Crustacea, Decapoda, Brachyura, Calappidae, deep water, Pacific Ocean, New Caledonia, new species.