I have referred previously to G. Karo and I. Lietzmann, Catenarum Graecarum Catalogus, published in the appallingly difficult to obtain Nachrichten der K. Gesellschaft der Wissenschaften zu Gottingen, Philologisch-historische Klasse, 1, 3, 5 (1902). In pp. 119-151, they classify catenas as types I-VII, following a scheme drawn up by E. Preuschen. This really should be online. Does anyone have a copy?
UPDATE: Apparently that volume of the Nachrichten is here. Thanks to Andrew Eastbourne for the tip.
UPDATE2: I’ve now edited that PDF, removed everything except the Catalogus, and uploaded it to archive.org by itself. It’s here. That should make it easier to find, and more accessible.
Of course now I need to read it…