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A new rhabdochonid nematode, Pancreatonema americanum sp. nov., is described from the pancreatic ducts of dogfish sharks, Squalus acanthias L., in the North Atlantic Ocean off the coast of Massachusetts, USA. Pancreatonema americanum sp. nov. differs significantly from the only other congeneric species, P. torriense McVicar et Gibson, 1975, on the basis of the following: absence of an unpaired median papilla and a pair of postanal papillae on the vesicular formation surrounding the cloacal aperture, absence of a rim surrounding the mouth and small single lateral cephalic papillae of the inner circle, considerably larger body and organ measurements, and host types (sharks vs. rays). The presence of a remarkable vesicular formation surrounding the cloacal aperture is the principle feature distinguishing Pancreatonema McVicar et Gibson, 1975 from Johnstonmawsonia Campana-Rouget, 1955.