107 



Mr. De la Beche observes, he has been unable to discover any of 

 the interesting beds of the upper grauwack6 noticed by Mr. Mur- 

 chison in Wales and the adjoining English counties. On the north 

 coast of Devon and its continuation into Somersetshire, precisely 

 where some traces of them should be expected, older beds are 

 brought up by contortion (Dunkeny Beacon), and the other high 

 land of the coast is formed of beds apparently of the same age with 

 those which extend from Hartland to the eastward, a great trough 

 being formed, supporting a body ofgrauwacke, the chief portion of 

 which is an argillaceous slate, calcareous matter being disseminated 

 in the lowest portion of it, often in sufficient abundance to constitute 

 limestone. 



The letter was also accompanied by a collection of specimens il- 

 lustrative of the cleavage of the grauwack^ in the neighbourhood 

 of Biddeford. 



A paper was afterwards commenced on the physical and geologi- 

 cal structure of the country to the west of the dividing range between 

 Hunter's River (lat. 32° south) and Moreton Bay (lat. ii7° south), 

 with observations on the geology of Moreton Bay and Brisbane 

 River, New South Wales, by Allan Cunningham, Esq., and com- 

 municated by William Henry Fitton, M.D., F.G.S. 



