This species is closely allied to _Fasciola hepatica_, but is distinguished by its elongated body, short cephalic cone, almost parallel sides, larger ventral sucker, which is also closer to the oral sucker, and by its larger eggs. Length up to 75 mm., width up to 12 mm. Oral sucker 1 to 1·2 mm., ventral sucker up to 1·7 mm. in diameter. Eggs 150 µ to 190 µ long by 75 µ to 90 µ broad. _Habitat._--Bile-ducts of _Camelopardalis giraffa_, _Bos taurus_, _Bos indicus_, _Bos bubalis_, _Ovis aries_ and _Capra hircus_. _Distribution._--Africa. This species has once been observed in man by Gouvea, in Rio de Janeiro, in a French naval officer who became ill with fever, cough and slight blood-spitting. The lungs were normal except for a sharply circumscribed spot at the base of the left lung. Twenty days later during a fit of coughing the patient spat up a fluke 25 mm. long, characterized by its slender aspect and by the size of its ventral sucker, and its close proximity to the oral sucker. Considering the fact that Gouvea’s patient had spent many weeks in July of the same year in Dakar (Senegambia), where according to Railliet _Fasciola gigantica_ is common in slaughtered animals, and considering also the characters of the fluke, Railliet rightly assumes that one had to do with the African giant fluke and that the patient had infected himself in Dakar. Sub-family. *Fasciolopsinæ*, Odhner, 1910. Genus. *Fasciolopsis*, Looss, 1898. Ventral sucker large, and elongated posteriorly into a sac. Cirrus pouch long and cylindrical, its greatest length being occupied by the sinuous tubular seminal vesicle, on which exists a peculiar cæcal appendage. Laurer’s canal present. *Fasciolopsis buski*, Lank., 1857. Syn.: _Distomum buski_, Lank., 1857; _Dist. crassum_, Cobbold, 1860, _nec_ v. Sieb., 1836. [Illustration: FIG. 146.--_Fasciolopsis buski_, Lank. _V.s._, ventral sucker; _C.p._, cirrus pouch; _I._, intestinal fork; _S.v._, vitellaria; _T._, testes; _O._, ovary; _Ms._, sucker; _Shg._, shell gland; _Ut._, uterus. Magnified. (After Odhner.)]