DAVIDSON — SCOTTISH CARBONIFEROUS BRACHIOPODA. 469 



6. Black limestone (impure) and shales ; Sonth-hill, Campsie. 



7. Main limestone, shale, and ironstone ; Campsie. 



8. Balgroclian Bum beds: slielly limestone, and shales; 



North-hill, Campsie. 



9. Mill Bum beds : limestone, ironstone, and shales ; 



Campsie. 



10. Balglass Bum beds : ironstone and shales ; Campsie. 



11. Craigenglen beds : limestone (impure), ironstone, and 



shales ; two miles south-west of Campsie 



12. Beds in the valley of Campsie, consisting of thin-bedded 



strata known only by boring. 



13. Ballagan beds : great thickness of thin-bedded nodular 



limestone, marly shale, and red and grey micaceous 

 sandstone ; north and west of Campsie. 



14. Old Red Sandstone, of a brick-red colour, and of great 



thickness : has hitherto yielded no fossils. 



The marine limestone and shale extend from Corriebum to the 

 Craigenglen beds, and belong to the lower marine hmestone forma- 

 tion of Scotland. In the valley of Campsie the upper marine lime- 

 stone is wanting. 



In Ayrshire, Arran, and Bute we find, with small local differences, 

 much of the same order of succession, and most of the fossils that have 

 been collected in Lanarkshire, Renfrewshire, Dumbartonshire, and 

 Stirlingshire. Near Dunbar, in Hadding-tonshire, w^e again find similar 

 shales and limestones replete with fossils identical with those which 

 abound in the parishes of Carluke, Kalbride, at Campsie, Lesmahago, 

 &G. And any one would at once conclude that aU represent the same 

 geological epoch. 



In the Lothians, as well as in Fife, the Lower Coal-measures are 

 stated by Mr. Page to have " none of the shaly character, but to 

 consist of thick-bedded sandstones, dark bituminous slates, bands of 

 ironstone, thin seams of coal, and peculiar strata either of shell-lime- 

 stone, or of argillaceous limestone, thought, from the fossils, to be of 

 fresh- water or estuary origin ; . . . . and that the lower group, as 

 developed in Scotland, differs little in appearance from the upper 

 group : hence the term ' Lower Coal-measures ' generally appHed to 

 it in that country." In these counties the Brachiopoda are not so 

 abundantly distributed as in the Clydesdale basin ; still the species 

 that have been collected at such places as Dryden, Courland, and 

 Scola Burn, near Edinburgh, as well as in other more distant locali- 

 ties, do not differ specifically from those found in the other counties 

 above referred to. 



We will here conclude the very few stratigraphical observations 

 we have thought necessary to introduce, and devote the remainder 

 of our paper to the description of the species of Brachiopoda that 

 have been hitherto discovered; and, although the series is nume- 

 VOL. II. u u 



