The oogenotop of Amphilina bipunctata (Cestodaria).

Amphilina bipunctata Riser, 1948 were collected from the white sturgeon Acipenser transmontanus from the Columbia River, USA. The morphology and histochemistry of the oogenotop of Amphilina as they pertain to egg formation are described. The vitelline gland granules secrete the main part of the egg shell. These shell granules are positive for basic proteins, SS groups, and there is a weak reaction for phenolase. The Mehlis gland granules are positive for PAS. The first-formed egg shell is positive for basic proteins and it is weakly positive for phenolase. These egg shells are negative for SS groups and PAS. Conjectures concerning the significance of these data are made.