Five species, 3 new, of myoxosporida in the genus Myxidium were recovered from 7 genera and 23 species of deepsea macrourids. Although some Myxidium species were geographically dispersed they showed remarkable spore size stability. Two forms, "long" and "stubby" are described for M. coryphaenoidium. Abnormal M. coryphaenoidium spores are shown to resemble superficially other species and genera.