166 



PKOCEEDINGS OE THE GEOLOGICAL SOCIETY. 



[Jan. 8, 



Gervillia aviculoides, Sow., sp. 

 Avicula, sp. 

 Pecten lens, Sow. 



— demissus, Phil. 



arcuatus, Sow. 



annulatus ? Sow. 



, sp. 



Gryphsea dilatata, Sow., var. /3, Phil. 



bilobata. Sow. 



Ostrea Marshii, Sow. 



archetypa, Phil. 



Sowerbyi, lye. et Mor. 



Tooth of a Saurian. 

 Wood [abundant). 



The beds lying directly on the calcareous sandstone of the " roof- 

 bed " consist of finely laminated sandy clay, with numerous crushed 

 bivalves, including Nucula nuda, Phil., small species of Pecten, &c. 

 They abound with specimens of the different varieties of Belemnites 

 Owenii, Pratt, and also contain Ammonites Gowerianus, Sow., A. cal- 

 loviensis, Sow., var., and GrypJicea dilatata, Sow. (small variety). 

 These beds must, from their palseontological characters, be classed 

 with the " roof-bed " in the lowest zone of the Middle Oolite, as 

 representing the Kelloway rock of England. 



At the section of Cadh'-an-Eigh on the coast of Rosshire, already 

 noticed (p. 125), the "roof-bed "is very distinctly seen, though, 

 like the coal-seam on which it lies, it is greatly reduced in thickness. 

 It consists of a sandy clay passing into a very hard ferruginous 

 and argillaceous sandstone, becoming in places calcareous from the 

 abundance of included fossil shells. The fossils are very numerous, 

 but badly preserved, the substance of the shells being almost always 

 in a soft and decomposed condition. The upper surface of the bed, 

 which is not more than a foot thick, is completely made up of Belem- 

 nites of all sizes, crowded together in great profusion. In the 

 abundance of Belemnites which it contains, the rock at Cadh'-an- 

 Righ differs from that at Brora; but there is the most complete 

 correspondence with regard to the rest of the fauna. 



Fossils from the " Roof -bed " at Oadh' '-an-Righ. 



Cuoullaea. 



Trigonia elongata, Sow. 



irregularis, Seeb. 



Myacites recurvus, Phil., sp. 



securiformis, Phil., sp. 



G-resslya peregrina, Phil., sp. 



Serpula. 



Wood. 



Belemnites Owenii, Pratt, var. torna- 

 tilis, Phil. Very abundant. 



, sp. 



Ostrea Marshii, Sow. 



Grypbasa dilatata, Sow. (small form). 



Pecten demissus, Phil. 



lens, Sow. 



Perna quadrata. 



Lima pectiniformis, Schloth. 



The roof-bed at this place, as at Brora, is covered by a thick 

 series of marine beds, to be more particularly noticed hereafter. 



B. Zone of Ammonites Jason, Wright. — The " roof-bed " at Brora 

 is overlain by a thick mass of argillo-arenaceous strata, crowded 

 with marine fossils. These are the strata pierced in the several 

 coal-shafts. There are great discrepancies in the accounts which we 

 possess of the beds passed through in the two principal shafts ; but this 

 may be accounted for (especially when we remember that one of the 

 sections is the result of a boring) by the variable character of the 

 beds, which throughout consist of combinations of sand and clay in 

 varying proportions, so that it is often difficult to decide whether 



