truncatulus harbours the Cercaria of Fasciola hepatica, the liver-fluke, which causes rot in sheep. Ancylus, which occurs in rivers, has a minute limpet-like shell.

For Fasciola hepatica, see Thomas, Quart.

Genera: (a) Pertusa laterali poro: Lumbricus, Sipunculus, Fasciola.

A, Fasciola hepatica, from the ventral surface (X 2); the alimentary and nervous systems only shown on the left side of the figure, the excretory only on the right; a, right main branch of the intestine; c, a diverticulum; g, lateral ganglion; n, lateral nerve; o, mouth; p, pharynx; s, ventral sucker; cs, cirrus sac; d, left anterior dorsal excretory vessel; m, main vessel; v, left anterior ventral trunk; x, excretory pore.

E, egg of Fasciola hepatica.

- Five stages in the life-history of Fasciola hepatica; all highly magnified.

bifurcated gut is not branched, unlike, for example, Fasciola.

truncatulus harbours the Cercaria of Fasciola hepatica, the liver-fluke, which causes rot in sheep. Ancylus, which occurs in rivers, has a minute limpet-like shell.

For Fasciola hepatica, see Thomas, Quart.

Genera: (a) Pertusa laterali poro: Lumbricus, Sipunculus, Fasciola.

A, Fasciola hepatica, from the ventral surface (X 2); the alimentary and nervous systems only shown on the left side of the figure, the excretory only on the right; a, right main branch of the intestine; c, a diverticulum; g, lateral ganglion; n, lateral nerve; o, mouth; p, pharynx; s, ventral sucker; cs, cirrus sac; d, left anterior dorsal excretory vessel; m, main vessel; v, left anterior ventral trunk; x, excretory pore.

E, egg of Fasciola hepatica.

- Five stages in the life-history of Fasciola hepatica; all highly magnified.