20 



The main limestone (e) is of marine origin, and has many remains. 

 The white limestone (/) is of fresh-water origin, and almost made 

 up of remains of cypridce, a family of crustaceans. The sandstone (g) 

 is that represented in the preceding cut as forming the higher parts 

 of Craigmaddie M'oor, in consequence of its gradual rise to the west. 

 The alum strata are mentioned farther on. 



17. The subdivisions of the Coal series, as given in two papers hy 

 the late Mr. John Craig, mining engineer and geologist, one published 

 in the Transactions of the Highland Society, vol. xii., or vol. vi., 

 New Series, 1839, the other laid "before the British Association in 

 1840, have not since been disturbed, and are generally received as 

 approximately correct. 



The entire series may be divided as follows : 



1. Upper Bed Sandstone series. 



2. Upper or fresh-water coal series. 



3. Upper marine series. 



4. Lower coal series. 



5. Lower marine limestone series, with intercalated fresh-water 



beds. 



6. The Ballagan series and Old Eed Sandstone, at the base of 



the entire formation. 



The first of these divisions has been considered to represent the 

 New Eed Sandstone series. It occurs in the higher part of the 

 central district, about Hamilton, Blantyre, &c., and consists of 

 variegated sandstones and marls, with a few thin coal seams, and 

 traces of plants ; and hence it seems hardly proper to place these 

 beds in the New Eed series ; but they have been as yet only partially 

 examined, and it may hereafter appear that the uppermost beds 

 really represent this formation in a rudimentary state. 



The upper coal series is of fresh-water or estuary origin. It reaches 

 from Glasgow due east by Garnkirk, north side of New Monkland 

 parish, towards Bathgate. South-west its west ooundary runs from 

 the trap hills at Dychmont by Drumpeller, Bellshill, Motherwell, 

 and Larkhall to Stonehouse ; thence by Carluke, east and north-east 

 towards Bathgate ; thus comprehending all the central fields in the 

 parishes of Camnethan, Shotts, Dalserf, Dalzell, with Old and New 

 Monkland. Limestones are absent, and are represented merely by 

 calcareous sandstones. The entire thickness is about 220 fathoms. 

 The testacea are all of fresh-water or estuary genera, as unio, anodon, 

 mytilus, &c. ; fish remains, and the usual coal plants abound. There 

 are nine beds of coal, whose aggregate thickness varies from 24 to 

 34J feet, and twenty-five minor seams, rarely passing 14 inches each, 



