Dr. Murai Éva szerk.: Parasitologia Hungarica 23. (Budapest, 1990)

Polymorphus magnus (Skrjabin, 1913) Specimens studied: No. 10607, 2 females from Ayihya fuligula, Biharugra, November 1985. Description (Table 7, Fig. 5): Female: Total length 10.29-12.54. Trunk fusiform, with constriction after its anterior widest part; 10.0-11.4 long and with maximum width 1.65-1.95. Anterior part (with length 1.35-1.40) of trunk covered with spines; length of spines 0.0175-0.0225. Proboscides of both specimens with not fully everted anterior parts; 0.294-0.438 long, with maximum width 0.244-0.263 and width at base 0.169-0.175. Armature consisting of 16 longitudinal rows of hooks; only posterior 5-6 hooks in each row seen, anterior hooks not studied. Largest hooks seen with blade 0.0575-0.0613 long and root 0.075-0.0775 long. Neck conical, 0.70 long and 0.33 wide. Proboscis receptacle double-walled, attached at proboscis base; 1.38-1.50 long, with maximum width 0.17. Lemnisci 2.70 long. Trunk full of eggs. Eggs elongate ellip-tic; external shell with many fine fibrillar structures; middle shell with polar swellings; eggs measure 0.088-0.144 x 0.016-0.025. Remarks: The specimens studied are morphologically similar to the description of PETROCHENKO (1958) which includes SKRJABIN's original description and is completed with additional data. The main differences concern the measurements of the roots of the largest hooks which in our specimens are up to 0.075-0.0775 (0.0712 in PETROCHENKO's description) and slightly larger eggs with maximum length 0.144 (0.139 according to the cited description). Table 7 Metric data of the hooks of Polymorphus magnus from Aythya fuligula - No 10607 Measurements in p.m N Blade Root N length thickness length thickness 1 57 5-57 5 15 0-16 3 60.0-62 5 15.0-15.0 2 60 0-61 3 17 5-20 0 77.5-77 5 17 . 5-17 . 5 3 57 5-60 0 20 0-22 5 75.0-75 0 20 . 0-22.5 4 47 5-50 0 12 5-15 0 5 40 0-45 0 12 5-15 0 6 32 5 The anterior hooks (1-2) are inserted