Abstract
Four new species of Henneguya (Myxosporidan) are described from Ictalurus punctatus Rafinesque (channel catfish). They are H. postexilis and H. longicauda from the gills; H. adiposa from the adipose fin; and H. diversis from the liver, kidney, connective tissue of muscles and fins, and tumor-like external growths. H. pellis sp. nov. is described from the dermis of I. furcatus (LeSueur) (blue catfish). The development stages of all described species are discussed. H. exilis Kudo was found on the gills of one I. punctatus; notes on its spore characteristics are presented.