1848,] MOORE ON FOSSILIFEROUS BEDS OF WIGTOWNSHIRE. 9 



Corswall Lighthouse . 

 Flaggy greywacke . . 



Conglomerates , 



Dally Bay 



Shales T 



and VCairnbrock. 

 Slate-^. J 



{Knock Bay. 

 Port Patrick. 



Morroch Bay 



Slates and Shales. 



Graptolites. 



Graptolites. 

 Mytilus (?) 



Pink Syenite . 

 Cairngarroch , 



Grennan Slates. 



Granite •< 



Mull of Galloway 



Graptolites. 



used for any but the poorer 

 farm-houses. I have thought 

 this granite worth mentioning, 

 as I am not aware that any has 

 been described as occurring be- 

 tween that of Cairnsmuir on the 

 Cree in Kirkcudbrightshire, and 

 that of the Mome Mountains in 

 County Down. 



From the bay of Drumore to 

 the Grennan, a distance of one 

 mile and a half, a mass of slates 

 which have been used for roofing 

 purposes dips to the north at a 

 high angle ; and after passing a 

 great mass of syenite at Cairn- 

 garroch, which has altered the 

 neighbouring rocks and invaded 

 them in the form of dykes, we 

 arrive at the Morroch Bay, one 

 mile and a half south from Port 

 Patrick ; here a thick mass of 

 shales, black, red and grey, in 

 a vertical position, occurs inter- 

 stratified with syenite and red 

 earthy trap : the black shales are 

 in some places full of grapto- 

 lites ; they are remarkably fissile, 

 splitting readily as thin as a card, 

 and their surfaces are marked by 

 minute specks of iron pyi'ites. 

 The red shales are similar to 

 them in every respect, except in 

 colour, and in not containing 

 fossils, — differences probably due 

 to their greater proximity to the 

 trap. Proceeding thence to the 

 north beyond Port Patrick, after 

 passing much greywacke, so in- 

 terfered with by a dark serpen- 

 tinous trap, as scarce to present 

 a trace of stratification, we arrive 

 at the bay of Porto Bello near 

 Cairnbrock, where there is a con- 

 siderable thickness of slaty shales 

 and flags, containing graptolites, 

 and what appears to be the cast 

 of a Mytilus. These beds dip to 

 the south at a high angle. About 

 a mile and a half further north, 



