LEIDY'S DESCRIPTIONS OF DISTOMA. 309 



together or separately, and one may be frequently more contracted than the other, 

 as is represented in fig. 4. In expansion the inner orifice usually appears round, 

 the outer one triangular. In the greatest degree of contraction the outer orifice 

 looks like a transverse slit with puckered edges as in fig. 3. 



The orifice of the ventral acetabulum when opened is transversely elliptical, 

 (fig. 5.) In some instances I have observed several round granular corpuscles 

 moving in the cavity of this acetabulum during its movements of contraction and 

 expansion. 



Dujardin* speaks of a Distoma found in the intestine and liver of Limaces, which 

 bears considerable resemblance to D. vagans. The latter is, however, larger, and 

 never occupies the position of the former. 



*Hi8t. Nat. des Hel., p. 472. 



