The Roman Map of Britain Mais Drumburgh or Bowness-on-Solway, Cumberland

Maia (R&C 154) s misread as a next
Magis (ND XL₁₄ illustration) This was copied from miscopied text. It is extremely unlikely that the original was illustrated.
Magis (ND xl₂₉ text) Maglone was written directly above Mais in the preceding line and Maglone's g was erroneously incorporated.
MAIS (Rudge Cup)
MAIS (Amiens patera)
MAIS (Moorland patera)

Ian G. Smith¹ questions the traditional assignment of Mais as 'Maia' to Bowness-on-Solway. He points out the discrepancy between the likely date of manufacture and purpose of the epigraphic sources and the period of occupation of the fort at Bowness. Why then would Mais be Bowness? Why would Drumburgh, logically the next in the sequence, be skipped? He neither questions the traditional form Maia, nor its proposed etymology, but correctly assigns it to Drumburgh. He does not equate ND's Magis with Mais. (Otto Seeck, editor of the Notitia Dignitatum equated Magis with Ravenna's Maia and the two epigraphic records. He also equated it with Ravenna's Maio, an understandable error.)

The order of the Rudge Cup, the Amiens patera, and the Ravenna Cosmography follows a  sequence along Hadrian's Wall. The Notitia Dignitatum names a string of  numeri  westward to Maglone Old Carlise. Magis is next on the list. I believe Mais, the epigraphically attested form, is British for moss - 'a swamp, a morass, a bog, esp. a peat bog along the Scottish border.' The name Mais 'the moss' is suitable for Drumburgh (NY2659). But, alas, such an etymology does little to seal the assignment. The moss of northwestern Cumbria extends from the coast inland  to a line from St. Bees to Burgh-by-Sands.

OE mos 'bog, swamp' and 'moss, lichen'
OE m‘os is 'moss, lichen' cognate with Latin musca, D. mos, G. moos, OHG mos, mios, Icel. mosi, Dan. mos, Sw. mossa, Russ. mokh
Under Mease p.281, Ekwall expressed the probability of an identical double meaning for mos as with m‘os. Perhaps the double meaning, apparently unique to Britain, evidences the assimilation of the original mais.
(See further under Mease, for the possibility of river-names derived from mais.)

1. Ian G. Smith, 'Some Roman Place-names in Lancashire and Cumbria', Britannia xxix (1998), 372-383 

With the discovery of the Moorlands patera, Coggabata seems injected into the series along the Wall. But further investigation leaves the consideration of the Wall as a continuous fortification across Burgh Marsh in question. This leaves open the possibility of a fort on the southern shore, which would be Coggabata. I'm not being difficult, I'd just like to see it right.