246 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 5, 



3. On Fossil Remains in the Cambrian Rocks of the Longmynd 

 and North Wales. By J. W. Salter, Esq., F.G.S., of the 

 Geological Survey of Great Britain. 



[Plate IV.] 



The occurrence of any organism in those ancient sediments which 

 have been so often called Azoic is of sufficient interest for an account 

 of it to be laid before the Society. We have hitherto been acquainted 

 with but one genus — and that doubtfully an animal or a plant — in 

 the oldest Cambrian schists of Ireland. No fossils from rocks of 

 this age have been recorded from England except the forms which I 

 now describe, and of which a brief notice was sent to the last meeting 

 of the British Association. They are a new Sea-weed, or Zoophyte, 

 traces of marine worms, and a Crustacean of the Trilobite group. 



When, a few years back, I crossed the Longmynd with Prof. 

 Ramsay and Mr. Aveline, the unaltered and flat-bedded sandstones 

 which abound on the eastern side, and which are quite unaffected by 

 cleavage, appeared most promising for fossil remains, if any organisms 

 existed at the time when these rocks were deposited. Some of these 

 beds were ripple-marked, and the sandstones and flaggy beds of 

 greenish-grey stone were evidently not deposits from very deep water. 

 I hoped, therefore, that at least Oldhamia or Fucoids might be 

 found in them, if not more highly organized fossils ; and in the 

 summer of the past year, I was able to devote three or four weeks 

 to the search. 



A Fucoid, or at least one of those doubtful fossils we are in 

 the habit of calling such, had been found by myself a few years 

 back in the Cambrian grits near Bangor. It may be briefly described 

 here. 



Chondrites, sp. 



The fossil alluded to is far too imperfect for any exact description to 

 be given of it ; yet, as it is the only species known in these old rocks, it 

 should be noticed. 



It occurs as elongated and nodular branches, generally ^ of an inch thick, 

 but of variable size, upon the surface of a coarse sandstone, the cleavage 

 of which interferes much with the shape of the fossil. It is even possible 

 that these apparent branches may have been produced by the crossing of 

 separate tubes, and that the whole may be due to large Annelides, the filled- 

 up burrows of which have a great resemblance to Fucoids, and are often 

 mistaken for them. 



Loc. Moel-y-ci, a mountain near Bangor (1850). — J. W. S. 



That there may be no doubt about the geological position of the 

 fossils about to be described, it is as well to say that they occur in 

 nearly vertical beds of hard flag-like sandstone, which run along 

 the strike of the Longmynd at about 1^ mile E. from the principal 

 ridge ; and they form part of a series of bluish-grey sandstones, 

 alternating with purplish slaty beds, which all lie below the conglo- 

 merates and red sandstones of the Portway, and above the thick series 

 of dark-olive schists which are seen so well at Church Stretton, All 

 Stretton, &c., and which are the lowest portion of the Longmynd 



