Not valid. A large Pennella species described from ocean sunfish (Mola mola) in the eastern Atlantic (Ireland). Wilson (1917) redescribed P. orthogorisci collected from ocean sunfish caught off Massachusetts. There is nothing within these two accounts which would indicate that this species differs in any way from P. filosa which was first documented from, and has repeatedly been found on the same host (Benz & Hogans 1993 and references therein). Wilson (1917) in redescribing P. orthogorisci, differentiated his specimens from P. instructa, but failed to explain how they were different from P. filosa. The morphological variability of specimens of P. filosa from ocean sunfish (Hogans 1988a) easily encompasses any features of P. orthogorisci. Synonym of P. filosa (Kabata 1979; Hogans 1988a). accepted as P. filosa (Walter & Boxshall 2015).