. Fresh-water biology. Freshwater biology. 378 FRESH-WATER BIOLOGY 25 (24) Genital hooks 32 in number. P, {Polyslomoides) opacum Stunkard 1916, Length 3 to 4 mm., width to i mm. Caudal suckers mm. in diameter. On caudal disc many small hooklets 7 to 9 yit long, and one larger pair, 75/i long; no great hooks present. Genital coronet of 32 (33^) equal hooks. Egg oval, by mm. Vitellaria of large compact folhcles under dorsal surface from pharynx to caudal disc except over ovarian complex; so extensively developed as to obscure internal organs and render body opaque. In esophagus
. Fresh-water biology. Freshwater biology. 378 FRESH-WATER BIOLOGY 25 (24) Genital hooks 32 in number. P, {Polyslomoides) opacum Stunkard 1916, Length 3 to 4 mm., width to i mm. Caudal suckers mm. in diameter. On caudal disc many small hooklets 7 to 9 yit long, and one larger pair, 75/i long; no great hooks present. Genital coronet of 32 (33^) equal hooks. Egg oval, by mm. Vitellaria of large compact folhcles under dorsal surface from pharynx to caudal disc except over ovarian complex; so extensively developed as to obscure internal organs and render body opaque. In esophagus of Trionyx ferox and of Malacoclemmys lesueurii; Texas. Fig. 658. Folysioma opacum. Extended. Stunkard.) Ventral view. X 7- (After 26 (14) Posterior disc overhung by a flap bearing four hooks. Diplohothrium F. S. Leuckart 1842. Elongate, ectoparasitic trematodes with slender posterior end. Six short stalked suckers arranged in two longitudinal rows and armed with chitinous hooks, stand just anterior to slender caudal tip which carries two hooks on each side. One species {D. armatum) reported on the gills of the lake sturgeon {Acipenser rubicundus) from St. Lawrence River. 27 (13) Posterior disc with two suckers. Sphyranura Wright Caudal lamina considerably wider than slender body, with two im- mersed suckers, two large hooks behind them, and sixteen small hooks arranged seven along each side of the lamina and one in each sucker. Two contractile bladders anteriorly, each with a dorsal pore. No lateral vaginae. Oviparous. Only species known. Sphyranura osleri R. R. Wright 1879. On the skin of Neduriis lateralis in the Great Lakes region. Corre- sponds to larval stage of Polystoma in having only two tenninal suckers. Fig. 659. Sphyranura osleri. Ventral surface. MacCallum.) X 20. (After Wright and. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
