Discipline: Veterinary Medicine
Pouched amphistomes from ruminants in the Philippines were collected and examined. These were fixed and stored in 70% ethyl alcohol. Specimens were hand-sectioned in the sagittal plane, stained in aceto-alum-carmine, cleared in oil of cloves and mounted in Canada balsam. Representative specimens were sectioned by the paraffin method, in the cross and sagittal planes, stained in Delafield's hematoxylin and eosin, cleared in xylene and mounted in Canada balsam. Among four other previously known species (Gastrothylax crumenifer, G. boyangensis, Carmyerius synethes and Fischoederius cobboldi), a new species Fischoederius upiensis from Bubalus bubalis and Bos taurus is identified, described and illustrated. F. upiensis is characterized by its small and almost oval size, ceca in median field with length of about 48% of the body length, anterior testis forming a bulge at the bottom of the ventral pouch and anterior to acetabulum, and ventral pouch nearly rounded in cross section. In median sagittal section, its pharynx is of the paramphistomum type, acetabulum of the fischoederius type and terminal genitalium of the leydeni type. It is differentiated from closely related species of the genus. On account of insufficient descriptions which are based on flattened specimens and lack of information on the features of the muscular organs, the following are considered species inquirendae: Fischoederius ovatus, F. boyangensis, F. compresus, F. explanatus, F. sichuanensis, F. ovis and F. bubalis. The taxonomic value of the pharynx, acetabulum and terminal genitalium as seen in median sagittal section for the family Gastrothylacidae is discussed.