Maxima.
Longa.
Brevis.
Semibrevis.
Minima.
Semiminima, which was added later.

Maxima.
Longa.
Brevis.
Semibrevis.
Minima.
Semiminima, which was added later.

As still smaller units of value were added, the semiminima was replaced by

, and the half semiminima thus became

, and the next smaller values,

and