AND THE ADJOINING DISTRICT, BERWICKSHIEE. 35 



Organic remains were first discovered among these sandstones, in the summer 

 of 1840^ in a fine section exposed by the Whiteadder about half a mie be ow Cock- 

 burn M 11 These chiefly consist of scales, occipital plates, xchthyodorulites, and 

 ler bony parts of the Hdopt.cMus NobUissi^nus. Similar remams also occur m 

 the sandstones directly opposite to Cockburn Mill, and m those to the east of the 

 Knocrwi They are not distributed uniformly through the stratam winch they 

 .r,f bu are found only in particular beds, in which they abound ; whi e very 

 eTo; nlHrl "be seen in'the adjoining strata. At Cockburn Mill, the .chthy- 

 IlL bl are situated within a hundred feet of the conglomei^te, from which 

 ty 're separated by a series of intervening beds of unfossxhfei-ous red sand- 

 tone and thin strafa of conglomerate. One bed which is exposed here contams 

 he remaL of the Holoptychius in such abundance, that a chip cannot be struck 

 Iff ^t^out disclosing a portion of a scale or plate. 'It is of a coarse, sandy, gntty 

 extu etdi generlllyso brittle from being highly impregnated wi«i ammal 

 r^a ter aTto be easily broken between the fingers. It is only a few mches thick. 

 Tme oV he ^iX beds with which it is associated also contain these fossils m 

 Is^^Ui:— nce,buttheyappeartobeingr^^^^^^ 



of each stratum few being found in the interior of a thick bed. These stiata pre- 

 sent be^Syrippled surfaces, and (especially the gritty bed above mentioned) 

 Tew otTer uneVivocal marks of littoral deposition. A circumstance which tends 

 troriy to favom- the view of their having been formed near the ^ho-' - 1/- f-«* 

 of It included remains being of such a fragmentary character, that although 

 Jeces scales and plates may be picked up in hundreds, it is very rare to find 

 one of either that is not more or less mutilated. Indeed, it would appear that aft^ 

 Is 1 fge fishes died, their osseous parts, being separated by decomposition an^ 

 the actio; of the waves, were tossed about on the sandy beach, -d exposed to at- 

 trition amon- the coarse sand and pebbles, until they were reduced to the frag- 

 mentarv state in which we now find them. The fact of the remams of the Holop- 

 ry^rbntchiefly found associated with appearances indicate 

 Ime shore, would almost lead one to suppose that these fishes were m the habit 

 tqSnt ng shallow water, perhaps because of their food bemg there more abun 

 dant At all events, their remains appear to be confined to these nppled strata ; for 

 fn the corresponding beds of the old red sandstone above Greenlaw, which are de^ 

 luute oSe marls, and bear evidence of having been deposited m deep water, 

 there are no traces of them to be found. 



On the east side of the Knock hill, the ichthyolitic beds of this onnation are 

 tilted up at high angles by the mass of grey porphyry of which that hill consists. 

 Th remains found here are of the same fragmentary character as those of Preston- 

 haugh, and abound most in a few thin sandy beds within a few feet of the por- 

 phyry They consist chiefly of the scales, plates, spmes, and teeth of a fish allied to 

 L Holoptychius, but differing from it in several particulars, the scales being more 



