What is Ad Assisas Capiendas?

Legal Definition
To take assises; to take or hold the assises. Bract, fol. 110a; 3 Bl. Comm. 185. Ad assisam capiendam; to take an assise. Bract, fol. 110b.
-- Black's Law Dictionary
Legal Definition
At the summoning of the assizes. See 3 Bl. Comm. 185.
-- Ballentine's Law Dictionary