The Head Organs of Cleidodiscus mirabilis (TREMATODA MONOGENEA)

Introduction: Little or no detailed description has been heretofore attempted of Cleidodiscus, the work to date having been confined to taxonomy and general morphology (Mueller, 1934 and 1937; Mizelle, 1938; Mizelle and Cronin, 1943).

The head organs and cephalic glands were chosen for this study because of their conspicuous nature in the living animal and, at the same time, their confinement to a relatively small anatomical area. Since no minute description of these structures is known, an attempt was made to discover their exact histologic nature. The methods to be used were to include well known techniques of fixation, sectioning, and staining, but, in addition, an attempt was made to try to evaluate the usefulness of the phase-contrast microscope as a supplementary tool especially for examination of living material.