A new species of lophogastrid mysid of the genus Lophogaster M. Sars, 1857 is described from four specimens collected in box-core samples between 46 and 99 m depth off the coast of Equatorial Guinea. Lophogaster eurylepis n. sp. is distinguished from other species of the genus by its central rostral spine being about twice the length of the lateral spines, the antennal scale being as wide as long, and the antennular lobe being continuously rounded without medial indentation at the pair of distal setae. The carapace is without tuberculation or postorbital spines, and the posterolateral spines are short.
Crustacea, Mysidacea, Lophogaster, Equatorial Guinea, eastern Atlantic, new species.