Ovary—very small, as in Fasciolopsis buski, on the right side.
Shell Gland—almond-shaped, 2·3 by 1·2 mm. In Fasciolopsis buski it is round and smaller, 1 to 1·5 mm. in diameter.
Vitellaria—similar in distribution to those of Fasciolopsis buski, but the acini are strikingly small.
Fig. 148.—Fasciolopsis fülleborni, ventral aspect. (After Fülleborn.)
Cirrus Sac—is the most characteristic feature of this species. It is a powerfully built, convoluted sac standing out clearly on the body. It is not a uniform, straight cylinder 0·25 to 0·33 mm. in diameter, as in Fasciolopsis buski, but even in fully extended flukes is typically convoluted. It is 1 mm. thick in the middle, but in other parts varies much from this. The posterior end of the cirrus sac is at two-thirds or more of the distance from ventral sucker to shell gland. In the case of Fasciolopsis buski the posterior end of the sac only extends half-way.
Seminal Vesicle—has a peculiar convoluted, saccular and angular course, but the cæcal appendage characteristic of the genus appears to be absent!
Excretory System.—The main stem gives off very regular transverse branches which are well seen posteriorly.
Eggs.—100 µ by 73 µ. Thin shelled.