Menachos 6:1

The handful of flour is taken from the following offerings, and the remainder of them goes to the kohanim: the offering of fine flour, of the frying pan, of the deep-fry pan, of cakes, of wafers, of a non-Jew, of women, of the omer, a sinner’s flour offering, and a sotah’s flour offering. Rabbi Shimon says that the handful is taken from a sinner’s flour offering brought by kohanim (even though the remainder is not eaten); the handful and the remainder are then offered separately.

Menachos 6:2

The flour offerings of kohanim, of the Kohein Gadol and of libations are for the altar and the kohanim do not receive a share from them; in these, the altar’s rights supersede those of the kohanim. The two loaves of Shavuos and the showbread are for the kohanim, and the altar does not receive a share from them; in these, the rights of the kohanim supersede those of the altar.