Cornovii (Cornwall) Dumnoniorum (present day Exeter), it is likely that he only listed Roman places, not purely native sites. Of these, there has been speculation that Voliba might be a place in Cornwall and Tamara is assumed to be on the River Tamar, the border between Cornwall and Devon. Ptolemy's list is supplemented by the problematical Ravenna Cosmography, which lists sixteen names before Isca Dumnoniorum (which is listed as "scadum namorum", showing some of the problems of this source) and which have therefore been assumed to be west of Exeter. Several have been identified as most likely in Devon, leaving "purocoronavis" (the
Celtic language decline in England a "vicus", and others end in elements denoting Roman features, such as "-caster", denoting "castra" ('forts'). There is a substantial body of names along the lines of "Walton"/"Walcot"/"Walsall"/"Walsden", many of which must include the Old English word "wealh" in the sense 'Celtic-speaker', and "Comberton", many of which must include Old English "Cumbre" 'Britons'. These are likely to have been names for enclaves of Brittonic-speakers─but again are not that numerous. In the last decade, however, scholars have stressed that Welsh and Cornish place-names from the Roman period seem no more likely to survive than Roman names in England: 'clearly name loss