306 /. Rogers &^ E. A. Newell Arber — Cuim of West Devon. 



district has been thoroughly searched by one of us, we have been 

 unable to find any other calcareous rocks. Such deposits have also 

 proved to be absent on the higher horizon in which the impure coal 

 or culm occurs in the neighbourhood of Bideford. The thorough 

 examination of these beds, which has been made during the collection 

 of the plant-remains already mentioned, has not resulted in the 

 discovery of any trace of a calcareous nodule. 



More recently attention has been turned to yet higher beds in 

 the Upper Culm Measures, which are stated by Mr. Ussher^ to 

 be somewhat dissimilar to the Culm Measures of the Bideford 

 district, and which he has distinguished as the Eggesford Grits. 

 In this work we have been assisted by a grant recently made 

 to one of us by the Royal Society Government Grant Committee, 

 and we may here express our great indebtedness for the removal 

 of many difficulties by this means. 



The Eggesford grits of Mr. Ussher consist of even-beilded sand- 

 stones and shales, and these may be studied in the fine coast-section 

 between Portledge Mouth and Windbury Point, a district which 

 may be conveniently termed the Clovelly district. This portion 

 of Devon is practically unexplored geologically. With the exception 

 of a brief notice of the Culm Measures near Clovelly, published 

 by Conybeare - in 1814, there is, so far as we are aware, no evidence 

 to show that it has ever been studied in detail. It may be pointed 

 out that Conybeare makes no mention of any calcareous deposits, 

 although such occur within a few yards of Clovelly pier. Pengelly' 

 and Townshend Hall also overlooked these beds, although well 

 acquainted with the district. 



Calcareous nodules have recently been found in several localities 

 along the coast to the west of Clovelly. They occur a short distance 

 from Clovelly, also below Gallantry Bower (on the south-east side), 

 and they have been found in association with the limestone described 

 here near Mouthmill, and also beyond Mouthmill in Beckland Bay 

 on the western side of Windbury Point.* They are found in certain 

 beds of shale, usually of 1-2 feet in thickness, which alternate 

 with the sandstones. The nodules are oval in form and of all sizes, 

 a rather large nodule measuring nine inches or more along its 

 greater axis. They effervesce freely with acid, and are crowded 

 with casts of Goniatites, similar to those mentioned below, which 

 are often preserved in calcite, although usually in rather indifferent 

 preservation. The thickest of these conglomeratic beds is that 

 associated with the limestone band at Mouthmill. 



In one locality the nodular beds are overlain by a thin band of 

 limestone,^ which is of special interest as being the only limestone 



1 Ussher: Trans. Inst. Min. Engineers, vol. xx (1901), p. 362; see also the 

 excellent geological map of Devonshire on pi. xvi. 



2 Conybeare: Trans. Geol. Soc, ser. i, vol. ii (1814), p. 495. 



3 Pengelly: Trans. Devon Assoc, vol. xvii (1885), p. 425. 



* The "Western Coast Section has not as yet been explored, but calcareous nodules 

 have been found a short distance to the south of Hartland Point. 



= The limestone was discovered by Mr. Eogers in August, 1903, when searching 

 for plant-remains on my behalf. — E. A. N. A. 



