Cyclocoelum microstomum and C. obscurum (Trematoda: Cyclocoelidae) from air sacs of waterfowl in Egypt: early life history, morphological and histological studies of adult.

Two species of genus Cyclocoelum are recorded from air sacs of waterfowls, collected from Egypt. Fully morphological and histological descriptions for the adult stage of C. microstomum from moorhen Gallinula chloropus are presented. Also egg and miracidium stages are described. The second species, C. obscurum collected from coat Fulca sp. also described. Some problematic status of the genus Cyclocoelum are discussed include evaluation of some morphological and histological criteria also the migration and location of worm within the birds.