Maybe I could have gotten the whole thing on an afghan needle but it was getting tight. The stitch here is called (I think) Tunisian net: instead of just looping the yarn over the needle in the first pass, you chain one at each stitch for a more open texture. And you cast on on stitch at the end of each first pass to keep rows even while still taking on two loops at a time. This is 60 stitches (give or take as you can see) by 90 rows. I have finally departed from the Dowager Duchess and started using stitch counters, which slows things down row by row but saves tearing out long stretches of miscellaneous length rows.
(sorry about the shadow; my attempt to show the stitch is even worse.)