Abstract
The Wet Sleddale extension of Manchester Corporation’s Haweswater scheme in Westmorland included the excavation of an aqueduct tunnel to the west of Shap village and entirely within the Skiddaw Slates of the Bampton Inlier. Excavated materials have provided abundant, well-preserved graptolites of late Didymograptus bifidus Zone (Lower Llanvirn) age and their description complements the revision by Jackson (1962) of the graptolite faunas, earlier than the D. bifidus Zone, of the Skiddaw Slates.