An interesting book was published last year: "The Catena in Marcum: A Byzantine Anthology of Early Commentary on Mark" by William R. S. Lamb.
This book, based on Lamb's dissertation, explores the background of the sources of the Catena that is often attributed to Victor of Antioch. It features an analysis of how the catena was made, and how it was treated as an "open book" which copyists felt free to adjust, rearrange, and sometimes supplement.
Lamb mentions that MS 304 -- a.k.a. as 194 in the catalogue of the National Library of France -- contains a text that is an expanded form of the catena; this is confirmed by J.R.R. Martin's observation (in his 1884/1886 work on NTTC) that it includes material from Photius. This is something to keep in mind when 304 is claimed to be a witness to the abrupt ending of Mark, especially when one also notices that in the Catena for Mark 16:1-8, Mark 16:9 is used (although I have no way of knowing if this is the case in the catena in 304 or not).
The book's publisher is Brill and currently it is for sale at Amazon for $182 (hardcover). I have posted a review at Amazon:
Readers expecting just an English translation of the Catena will be happily surprised to find some additional resources.
Y'know, harmonization to the surrounding context is sometimes identified as the source of textual variants. I wonder how much conformation to the nearby catena has affected the text in some of the MSS that have the catena framing the text of Mark.
Yours in Christ,
James Snapp, Jr.