W. A. E. Ussher — Palceozoic Rocks of Devon and Somerset. 447 



and Span Head, where the basement series of purple slates makes its 

 appearance. The junction between the Pickwell slates and the 

 green Lingula slates of the Baggy beds is perfectly conformable, 

 being well shown on the coast, and to the south of Loxhore. 



Owing to synclinal structure the Pilton and Baggy beds make a 

 re-entering angular projection with the Pickwell Down series on the 

 west of North Molton Kidge. The Pilton and Baggy beds occupy 

 a superficies of about 105 square miles. 



The Baggy beds are composed of green slates containing Lingula, 

 and brown micaceous grits and flags containing Cucullcp.a. The 

 brown grits extend eastward from the coast to Benton, near Stoke 

 Elvers resting upon the green slates, but further east they are 

 scarcely recognizable as a stratigraphical horizon, the Baggy beds 

 being frequently cut out by faults between Dulverton, North Molton, 

 and East Buckland. Brown grits containing CuciiUcea occur above 

 the green slates near Witherwind on the south of Haddon Down ; but 

 CucuUcea has been found by Mr. T. M. Hall in slaty red-brown 

 grits at the base of the green slates in the vicinity of the Tone 

 Valley. As grits occur in the Pilton slates, the CucuUcea zone could 

 only be distinguished by the discovery of its characteristic fossils in 

 the district east of Stoke Elvers, whereas the green slates may be 

 regarded as a persistent stratigraphical horizon. 



The Pilton beds consist of dull greenish and bluish-grey argilla- 

 ceous slates, occasionally containing thin strips of calcareous matter 

 generally dissolved away and leaving a brownish friable fossiliferous 

 residuum. They contain a marked development of grits near 

 Brauntou, Clayhanger, and Stawley ; grits occur also at various 

 horizons in the intermediate localities. The Pilton beds being much 

 plicated, the appearance of grits in them renders the detection of the 

 Cucullcea zone in the district between Dulverton and East Buckland 

 very uncertain. Bands of grit running from Hele Bridge, near 

 Dulverton, toward West Anstey, and on the south of North Molton 

 and north of Castle Hill, suggest anticlinal axes of the CucuUcBa zone. 



The Pilton beds make a most unsatisfactory junction with the 

 Culm Measures ; they frequently exhibit contrary dips in its vicinity, 

 probably due to inverted anticlinals, and the line where the junction 

 should occur coincides with a strip of old alluvial land cutting across 

 the present north and south courses of the streams, and in part con- 

 cealed by the alluvium of the Eiver Yeo. Near Dulverton Station 

 the distinction between the Pilton and Culm Measure slates appears 

 to be purely palgeontological, and south of Clayhanger and Stawley 

 there is every reason to conclude that their junction is perfectly 

 conformable ; at Morebath fault junctions complicate the relations 

 of the beds. 



Igneous Rochs. — Notwithstanding the existence of G-ranite at 

 Lundy, and the appearance of alteration in the Lower Culm Measures 

 of Coddon Hill, etc., igneous rocks are seldom met with in the 

 Palseozoic area of North Devon and West Somerset. Traces of 

 igneous rock occur in the Lower Culm Measures in two or three 

 places near Fremington (Sheet 26). The junction between the 



