The Roman Map of Britain Duriarno Ide? or Holsworthy, Devon?

Duriarno (R&C 12) NEXT

This site could be north of Teignbridge on Margary 491 or west of Okehampton on Margary 492.

    The Dawlish makes a very close approach to M491 in the Grammarcombe Wood above Ashcombe SX9080. Were Duri- to be for Dubi-, then perhaps here. Ideally, a dub-elis would be expected, but a dub-i-arno is not without merit. I am unaware of any Roman presence at this point.
    Farther on toward Exeter is the Roman fortlet at Ide (possible signal station) SX885889. The place-name Darnaford SX8689, earlier Darniford; if it is not from OE dierne, derne 'secret, hidden', could play a part. Does Darni- represent an old river name or a site that may be reached by way of the ford? Perhaps it can be compared with Dearne and Dorn. The first element of what is recorded as Durocornovio contracted to the modern name Dork. 
    But the fort at Ide seems well off the Roman road.
    Closer to the River Exe is EHNMR-636736 NE OF PEAMORE COTTAGE/POND FARM Roman enclosure SX9288.

    From west of Okehampton- Sourton Down on M492.

    Another Roman road, known as NMR Linear 670 may run northwest from Okehampton to Bude (unknown to Margary). It would pass through Holsworthy at the crossing of the River Deer SS345034. No early forms of the river name are known, but Gover proposed a relationship between Deer and Derriton aqua de Dyraton 1282, though he thought it a back-formation.
    This road would also cross the upper Tamar at Tamarstone Bridge ST283055, potentially the site of a Tamaris.

    And one more possibility -
EARTHWORK ENCLOSURE 330YDS (300M) SW OF THREE HORSE SHOES INN SX9095 on Star Barton Brook near Margary's M493 on the way to Crediton from Exeter where the name Duryard turns up. This rectangular enclosure is at least 50 x 50 meters, with one side eroded by Star Brook. It appears that Duryard is interpreted as 'deer park', as in AHDS 'Possible site of a Saxon deerpark'  SX 91 94 NMR_NATINV-448458. The earthwork listed is SE of South Duryard Farm SX9096, nearby are Duryardwood Lane (Track), Copse and Brook, with the village of Duryard at SX9194.