1866.] 



JUKES — OLD BED SANDSTONE AKD DEVONIAN. 



365 



Species. 



Bellerophon globatus. 

 Athyris concentrica , 

 Chonetes Hardrensis . 



Orthis interlineata . 



striatula 



Khynchonella pugnus 



pleurodon 



Spirifera leevicosta vel ostiolata 



Spiriferina eristata, t'«r. octo- 



plicata- 



Strophomena rhomboidalis 



Streptorhynchus crenistria 

 Phacops latifronst 



South. 



{Pilton 

 Brushford . 

 Marwood.... 



Pilton 



{ Barnstaple, 

 \ Braunton 

 [ Marwood 

 r Barnstaple . 

 < Croyde .... 

 [ Marwood. . . . 



Pilton 



Pilton (?) .... 



Pilton 



Pilton 



j Pilton 



{Barnstaple . 

 Braunton . 

 Marwood.... 



Pilton 



Barnstaple . 

 Braunton 



Korth. 



\ Woodabay 

 Ilfracombe . . 



I Lyntou .... 



I Haggington 

 \ Hill, near 

 J Ilfracombe . , 

 Ilfracombe .... 

 Ilfracombe .... 



Ilfracombe 



Lynton 



Ilfracombe 



1 Haggington 

 V Hill, near 

 J Ilfracombe .. 



Ilfracombe...., 



Lynton j Bailj'. 



Authority. 



PhilHps. 

 DaTidson. 



I may be pardoned, perhaps, for anticipating a considerable ac- 

 cession to this list when a thoroughly exhaustive search has been 

 applied to the country J. 



12. Considerations on the Devonian Fossils. — As many persons will 

 be inclined to place great reliance on the Devonian fossils as fixing 

 the place, or the age, of the Devonian rocks, it is advisable to deter- 

 mine the precise value of this evidence. 



In the first place, I would remark that the problem to be solved is 

 restricted within narrow limits. The question is, to which of the 

 two conformable groups of beds — the Carboniferous Limestone or 

 the Old Red Sandstone — do the Devonian beds belong ? 



■^ StropTiomena dcjiressa (formerly LcptcBna and Troducta depressa), and S' 

 rugosa and analog a are now included under 8. rhoonhoidalis, by Mr. Davidson. 



t Specimens of this trilobite were procured by me from the late Mr. Symonds 

 of Braunton, and collected by myself at Lynton last year; it occurs also at 

 Pilton and elsewhere. 



I This anticipation has already been partly verified. In the number of the 

 ' Geological Magazine,' for April last, was a letter from Mr. Spencer George 

 Perceval, of Severn House, Henbury, Bristol, giving an account of some fossils 

 he had found near Witthycombe, a couple of miles south of Dunster. The beds 

 are an extension of the Combe-Martin beds, but not only do they contain, 

 according to Mr. Perceval's determinations, at least fourteen species of Devonian 

 corals, hut a large s'pecies of Cucullcea, together with Terebratula?, Spirifera?, &c. 

 It will be interesting to know whether this Cucullcea is the same as one from 

 Marwood or Braunton, or is the Cucullcea Griffithii of Ireland. 



I would also beg leave to take this opportunity of asking Pala2ontologis(s 

 whether there is any great difference between the Myalinaim-mihe Carboniferotis 

 rock of Scotland (Carluke and Pitlossie), and that from Hangman Hill, near 

 Combe-Martin. Both specimens are in the Museum of Practical Geology in 

 Jermyn Street, (Note added in July as the paper passed through the press.) 



