AbstractA light and electron microscopic re‐investigation of the pancreatic islet organ of the hagfish,Myxine glutinosa, has confirmed earlier observations that agranular and granular β‐cells are the predominant cell types. However, in addition a rare second granular parenchymal cell was observed in which the granules are spherical in shape with a mean diameter of 213 nm, contrasting with the predominantly ellipsoid granules which characterise the β‐cell. At present, this allegedly second granular parenchymal cell cannot be unequivocally equated with a named islet cell type and its nature remains somewhat prob