Skin is an occupational surname, short for Skinner. Its origin in Cornwall is unambiguous. Several men named Skin lived in the parishes around Saltash in 1544. Later, the surname cropped up further west, which may indicate migration or could just be independent examples of this variant. Nonetheless, south-east Cornwall remained the preferred home for this name, with the majority of the handful of Skin families in 1861 being found in the parish of Menheniot.
The other two surnames come from placenames. Sparnon or spernan is the Cornish word for a thorn tree. There are at least five places with this name. Interestingly however, the first record I have, a David Sparnon at St Clement next to Truro, was not living in one of those five places. Perhaps there is a lost place-name, but otherwise the nearest Sparnon to Truro is either Redruth or Budock. In fact Breage was the centre of this family name in the 1500s. From there it either spread east and west or there were multiple simultaneous origins. In 1641 the name was found spaced quite widely from Gwinear and Gunwalloe in the west to Lanhydrock and St Blazey in the east. However, the Sparnons of the central mining district were the most prolific and by 1861 the name was found only in the Camborne-Redruth area.
Spettigue was first found as Spetego in North Tamerton, on the border with Devon. After the mid-1500s it spread from there to other parts of north-east Cornwall, where it was still most common in 1861. Meanwhile the name had mutated from Spetego to Spettigue by the 1580s as it moved out of North Tamerton. But it has an earlier history. Despite its location it’s from a Cornish placename – Trespettigue in Altarnun. It had presumably migrated eastwards from there between the 1300s and 1500s. Trespettigue was found as Trespethegou in 1401 and Rospethigou in 1332. Ros means a moor but spethegou or pethegou is less clear. Could it be from spethas – brambles, meaning something like moor of the little bramble patches?