A nine-line stanza of iambics rhymed a b a b b c b c c. The first eight lines are pentameters; the final line is a hexameter, in other words an Alexandrine.
Editors. "Spenserian Stanza". The Literary Encyclopedia. First published 01 November 2001
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1031, accessed 30 March 2015.]