REDESCRIPTION OF PETASIGER-EXAERETUS DIETZ, 1909 AND P-PHALACROCORACIS (YAMAGUTI, 1939) (TREMATODA, ECHINOSTOMATIDAE), PARASITES OF CORMORANTS

Two echinostome trematodes of the genus Petasiger, P. exaeretus Dietz, 1909 and P. phalacrocoracis (Yamaguti, 1939), parasitising cormorants (Phalacrocoracidae), were found in Phalacrocorax carbo L. from the Cz ech Republic. Both taxa are redescribed and literary data on their occ urence in cormorants are reviewed. The species P. exaeretus appears to be a rather rare species, hitherto recorded in Phalacrocorax carbo in Europe, Kirghizia and Azerbaidzhan. P. baschkirovi Ablassov and Iksan ov, 1959 is synonymized with P. exaeretus. P. phalacrocoracis (syn. P. hospitale (Mendheim, 1940) and P. exaeretus auct. nec Dietz, 1909), w hich has previously been misidentified and erroneously designated as P . exaeretus, appears to be the commonest species of the genus, parasit ising cormorants in the Palaearctic Region (Europe, CIS [USSR], Japan) and in Australia. Differential diagnoses of both the above mentioned species are presented.