Abstract A general account of the lower Paleozoic rocks in the Southern Uplands is given in The Geology of Scotland (Walton, 1965a, b); however, additional information now has been gained. Southernmost exposures along the Solway Firth long have been regarded as Wenlockian. Recent work on graptolite faunas has shown a narrow strip to be of Valentian age (Clarkson et al ., in prep.). The structure of southwest Scotland has been interpreted in terms of complex monoclines or markedly asymmetric anticlines which descend, cascadelike, northwestward (Walton, 1961). This main fold phase, regardless of interpretation of fold styles, always has been regarded as post-Silurian. Shiells and Dearman (1966) have raised the possibility of an earlier (Late Cambrian) fold episode in rocks of the northeast coast (Berwickshire) which they suggest might be Cambrian; however, no conclusive evidence has been adduced for the age of these rocks. The sequence consists of graywacke, siltstone, and shale, as well as conformable quartz keratophyre sheets. In discussing the possible age, Shiells and Dearman failed to note that quartz keratophyre is known from upper Ordovician rocks in Peeblesshire.