Arachnoidea dhondti, a new species of bryozoan from the North Atlantic (Bryozoa, Ctenostomata).

A new species of the ctenostomatous bryozoan genus Arachnoidea, Arachnoidea dhondti, is described. The species is epizooic on the hermit crab Parapagu rus pilosimanus collected in the North Atlantic off the coast of North Caro lina, USA at a depth of 550 m. The colonies are encrusting, forming linear chains or small patches on the anterior appendages of the hermit crab. The zooids consist of a short, proximal part, an oval middle part, together for ming a broad basal plate, and a distal part forming an erect tube-shaped pe ristomium. The species is distinguishable from other members of the genus b y a row of crystalline structures along the lateral margin of the basal pla te. The crystalline structures are considered to be homologous with the cre nellations in other species in the genus.