604 PKOCEEDINGS OP THE GEOLOGICAL SOCIETY. 



Park, continuously expose the variegated Upper Old Eed Sandstones 

 dipping S. 30° to 45°, as along the whole strike from Yention, at 

 the south part of Morte Bay, to Dulverton &c. 



In this traverse, as in the one made down the Rivers Exe and Barle 

 over the Dulverton area, and in two made between the Ilfracombe 

 and the Muddiford Yalley, via Bittadon, over and across the same 

 beds, I failed to detect any evidence of either fault or anticlinal other 

 than such as would be caused by slight rolling or undulations of the 

 beds from north to south ; and while helotu, in the Morte series, 

 the slates were conformable to the Pickwell Down Grits, or Upper 

 Old Eed Sandstone, above they gradually passed into the pale-yellow 

 and brown slaty and calcareo-siliceous Upper Devonian series of 

 Baggy, Marwood, and Sloly &c. 



2. Little Hangman and West Challacomhe to Ilfracomhe ; Ilfra- 

 combe to Baggy Point via Morte Bay. — I now return to the junction 

 of the red fine-grained grits of the Little Hangman with the fos- 

 siliferous slates of Combe Martin Bay. In West Challacombe Bay 

 the lowest or Stringocephalus-slates of the Ilfracombe group may 

 be examined in detail, where they repose upon the red, grey, and 

 yellow mottled grits of the Little Hangman and Knap Down, 

 further to the east ; the junction is also traceable up the road from 

 Combe Martin, leading to Knap Down Mine ; and in the bay the 

 passage takes place through a series of alternating or interstratified 

 siKceous red grits and fossiliferous slates, which finally assume their 

 persistent grey slaty character on the coast and in the valley; 

 they dip S.E. 35°. There are numerous intermittent beds and 

 masses of impure and subcrystalline limestones through the entire 

 course of these lower slates ; and the purer limestones of Combe 

 Martin, Hagginton, Helesborough, and Ilfracombe, when carefully 

 examined, form an important feature in the structure of the country ; 

 they strike west and east through North Devon and on into the 

 Quantock Hills in West Somerset. The aggregate thickness of these 

 lenticulaiiy bedded and apparently disconnected (on the line of 

 strike) masses of impure limestones is very great, equal to the more 

 massed and definite series at IN'ewton Bushel, Torquay, &c. ; and to 

 a large extent they contain the same fossils, and a large and well- 

 marked Middle Devonian fauna illustrates this area ; but, imperfect 

 as the organic remains necessarily are, through cleavage and exces- 

 sive induration of the harder rock-masses, I hope to show that 

 they, together with those of the Lower Devonian of the Lynton 

 area, belong to a group unmistakeably and essentially identical 

 with beds of the same age in Rhenish Prussia, Belgium, and the Bas 

 Boulonnais in France. This question will be gone into in my 

 remarks upon the palceontological value of the fossils of the De- 

 vonian group of rocks. The slates and grits of Combe Martin Bay 

 require much and careful investigation, owing to disturbance and 

 faulting. There is doubtless a rich fauna in the indurated siliceous 

 sandstones that are interstratified with the slates on the eastern 

 side of the Bay : it is here, and in these beds, that the large Strin- 

 gocephalus (S. Burtini) occurs, apparently below which, in the 



