. Fresh-water biology. Freshwater biology. PARASITIC FLATWORMS 395 Q9 (loo). Oral sucker smooth; not provided with muscular papillae around anterior end '. . Allocreadium Looss 1900. Esophagus long, not dividing until just before the acetabulum. Ex- cretory bladder very short, ending at posterior margin of posterior testes. Ovary spherical, lateral; vitellaria exclusively ventral. Cirrus and sac rather short; prostate well developed. Genital pore median. Eggs without filament, large (60 to 90 ij.) with light yellow shell. Intestine of fresh-watfr fishes. Several species from stomach and intest
. Fresh-water biology. Freshwater biology. PARASITIC FLATWORMS 395 Q9 (loo). Oral sucker smooth; not provided with muscular papillae around anterior end '. . Allocreadium Looss 1900. Esophagus long, not dividing until just before the acetabulum. Ex- cretory bladder very short, ending at posterior margin of posterior testes. Ovary spherical, lateral; vitellaria exclusively ventral. Cirrus and sac rather short; prostate well developed. Genital pore median. Eggs without filament, large (60 to 90 ij.) with light yellow shell. Intestine of fresh-watfr fishes. Several species from stomach and intestine of sheepshead, pumpkin- seed, sturgeon, sucker, dace, minnow, and gall-bladder of red-finned min- now. Collected in Great Lakes region. Lake Erie, Ontario; Lake Sebago, Maine. Synopsis of genus by Walhn. Young forms of A. commune Olsson encysted in Mayfly nymph {Blasturus cupidus Say) with eggs and Uving miracidia in body cavity of nymph (Cooper). Representative American species. Allocreadium lohatum Wallin 1909. Length 4 to 7 mm., breadth i to mm. Suckers equal, to mm. in diameter. No prepharynx; pharynx to mm. long by mm. broad. Testes lobed; cirrus sac extends to center of acetabulum. Ovary spherical; vitellaria postovarial, profuse, confluent behind posterior testis. Receptaculum large, pyriform, between ovary and anterior testis. Uterus compact, between anterior testis and acetabulum. Eggs very nmnerous, 67 to 85 11 long by 46 to 57 11 broad. Fig. 683. Allocreadium lobatum. Uterus indicated by dotted area, added from slide. X I9- (After Wallin.) 100 (99) Six oral papillae surround anterior end. 101 (102) Genital pore anterior to fork of intestine. Crepidostomum Braun 1900. Bifurcation of intestine just anterior to acetabulum. Excretory bladder elongate. Cirrus sac muscular; pore anterior to fork of intestine; testes large, round, median, halfway from acetabulum to posterior end. Vitel- laria confluent behind testes. Uterus short, with few egg
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
