Dr S. C. M atthews commented: “Those who make it their business to offer radiometric datings will always, to their credit, include a comment on the limits of accuracy of their estimates of age. But occasionally they attempt to equate their result with a named fold-phase (such as ‘Bretonic’ or ‘Sudetic’) and they take little account of the fact that references to fold-phases might also deserve to be accompanied by a comment on limits of accuracy, in this case stratigraphical. Named fold-phases appear to be available as convenient pegs on which to hang radiometric results. It should be understood that such pegs are not always firmly fixed. The equation of radiometric result with fold-phase may be criticized in another way. The radiometric information refers, presumably, to events which progressed at some depth in the accumulated pile of rocks, whereas the fold-phase, evident as an unconformity, refers to events at the surface. It is perhaps justifiable to ask for a reassurance that the event at depth must always have expression at the surface. If we accept the results presented in this paper at their face value, we can proceed to some comments on surface–depth relationships in the Variscan pile of south-west England. First, there is Dr Dodson's reference to a 345 to 365 m.y. event recorded in the rocks of south Cornwall. Dr E. M. L. Hendriks has recently reported that limestone within the Mullion Island lavas produces conodonts which Dr W. Ziegler has identified as being of Upper Devonian age.