Zoosystema
46 (11) - Pages 269-284Porcellanasteridae Sladen, 1883 is a family of mud-dwelling sea stars, living in bathyal and abyssal environments. Among the twelve currently recognized genera of this family, Benthogenia Fisher, 1911 is the only one known occurring at depth shallower than 1000 m. Benthogenia differs from all other porcellanasterids by having cribriform organs between all its marginals, from the disc to the tip of the arms. Benthogenia cribellosa Fisher, 1911 is reported from a locality as shallow as 111 m, and a new species, Benthogenia mahi n. sp., is described from material housed in the Muséum national d’Histoire naturelle, Paris (MNHN). Benthogenia mahi n. sp. is represented by twelve specimens, collected at depth ranging from 400 to 1200 m during four different expeditions. Benthogenia cribellosa is represented by two specimens from the MNHN, plus the holotype and two specimens from the National Museum of Natural History (Smithsonian Institution), Washington D.C. Benthogenia mahi n. sp. differs from B. cribellosa mostly by having more robust arms, fewer oral and adambulacral spines, and by the cribriform organs not covering the entire surface of the superomarginals of the disc. Molecular data (16S rDNA) were also used as an independent dataset to test for divergence between the two species. Benthogenia mahi n. sp. occurs in New Caledonia, Solomon Islands and Vanuatu, whereas B. cribellosa is only known from the Philippines. Detailed descriptions of both species are provided, as well as a detailed description of the skeleton of the new species.