Medieval Writing has a brief history of punctuation, with examples
http://medievalwriting.50megs.com/writing.htm
Manuscript Studies, Medieval and Early Modern
(http://www.ualberta.ca/~sreimer/ms-course/course/ms-intro.htm)
says (everything you'd ever want to know about medieval punctuation)
it was placed at the baseline to mark a pause in the middle of a sentence (roughly like our comma),
in the middle for a longer pause between clauses (roughly like our semicolon),
and at the headline for a long pause at the end of a sentence.
The punctus is the ancestor of our modern "period."
Punctus elevatus (which looks like an inverted semicolon, with the tail going up and to the left):
used from the twelfth to the fifteenth century,
The modern form (?) and usage is a seventeenth-century invention.
Virgula suspensiva (/): in common use from the thirteenth to the seventeenth century.
It could be made increasingly emphatic by doubling or even tripling.
Colon (:): first appears in late fourteenth century, to mark either a full or a medial pause.
Parentheses or brackets: a fifteenth-century invention, to mark parenthetical material;
)here are some medieval brackets(.
Exclamation mark: a modern invention, introduced in the seventeenth-century.
Quotation marks: an eighteenth-century invention.
Dash: an eighteenth-century invention.
Paragraphus (a "gallows-pole" or upper-case gamma, or § later ¶): used to mark paragraph divisions.
Later : Doh! There are two question marks in the piece. I'll use the modern version - there's one suggested in the Bedford Psalter analysis of the Historic Source Book for Scribes, on page 92.