Abstract
A description is given of Squalotrema llewellyni gen.nov., sp.nov., a monocotylid monogenean from the nasal fossae of the spur-dog Squalus acanthias. The parasite differs from representatives of other monocotylid genera in the number and arrangement of loculi on the haptor. In order to accommodate the genus Squalotrema, the diagnosis of the subfamily Merizocotylinae (Yamaguti, 1963) has been amended.The eggs differ in shape from those of other monogeneans. Each egg appears to be derived from a tetrahedron by flattening of one of the four apices. A long, coiled appendage projects from the flattened apex and the face of the egg from which the appendage projects also bears two spurs. The curved body of the fully developed, ciliated oncomiracidium occupies only two of the three rounded corners of the egg.