Þumla ‘Þumli’: This seems to refer to the southern part of the island of Hisingen at the mouth of the Götaälv, but whether it is acc. sg. of a p. n. Þumli or acc. pl. of the ethnic name Þumlar is unclear. It is taken here as a p. n., equivalent to Tumlahede/Tumlehed (following Skj B and ÍF 28). The folk-name is slightly favoured in LP: Þumli.