. Fresh-water biology. Freshwater biology. 388 FRESH-WATER BIOLOGY 61 (50) Oral sucker, subterminal; acetabulum divided by transverse ridge into two pockets. . Subfamily Zygocotylinae Differs from all other subfamilies in position of oral sucker and peculiar character of acetabulum. Testis lobed; cirrus sac lack- ing. Representative American genus. Zygocotyle Stunkard 1916. Acetabulum consists of anterior part extending dorsad and anteriad into body, and posterior overhanging lip bearing on each side conical projection. Posterior end of esophagus surrounded by muscular bulb in which fib
. Fresh-water biology. Freshwater biology. 388 FRESH-WATER BIOLOGY 61 (50) Oral sucker, subterminal; acetabulum divided by transverse ridge into two pockets. . Subfamily Zygocotylinae Differs from all other subfamilies in position of oral sucker and peculiar character of acetabulum. Testis lobed; cirrus sac lack- ing. Representative American genus. Zygocotyle Stunkard 1916. Acetabulum consists of anterior part extending dorsad and anteriad into body, and posterior overhanging lip bearing on each side conical projection. Posterior end of esophagus surrounded by muscular bulb in which fibers are not arranged in concentric lamellae as in other amphistomes. Vitellaria well developed, with large follicles, in extracecal region from oral sucker to acetabulum. Uterus and germ glands intracecal. Eggs numerous, by nim. Type species. Zygocotyle ceratosa Stunkard r9i6. From intestine of Anas platyrhynchos; Nebraska. Fig. 674. Zygocotyle ceratosa. Ventral view. X S. (After Stunkard.) 62 (49) Acetabulum conspicuously ventral and usually anterior to center of body. Reproductive organs completely or largely posterior to acetabulum. . 63 63 (160) No holdfast organs present except oral and ventral suckers. No sharp separation between anterior region with holdfast organs and posterior region with genital organs. Suborder Distomata . 64 64 (159) 65 (148) 66 (107) Hermaphroditic distomes. . Ovary anterior to testes. 6S 66 Coils of uterus do not extend posteriad beyond testes, or at most not beyond the posterior testis . 67 Bunodera (103 in this key) and Cryptogonimus (106) are exceptions. 67 (106) Acetabulum a single typical sucker which may be stalked or united with special genital sucker but is not divided 68 68 (los) 69 (74) Not more than two testes present. .... 69 Both ovary and testes dendritic; uterus limited to a restricted area 70. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - col
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
