848 



DR B. N. PEACH AND DR J. HORNE ON 



Glencartholm volcanic tuft", occupying the same relative position as the Lawston seams, 

 but too thin to be of any economic value. They are visible also in tributaries of the 

 Esk, on both sides of Glencartholm, where, as in the Esk, they frequently have lime- 

 stone roofs. 



A limestone, from six to eight feet thick, almost immediately overlies the coal 

 formerly wrought at Lawston Linn, which, from the fossils given in the annexed list, is 



of undoubted marine origin :- 



Clisiophylhom sp. 

 Lithostrotion casspitosum, Mart. 

 Athyris arnbigua, Sow. 



Productus giganteus, Mart. 

 „ pundatus, Mart. 

 Spirifera trigoncdis var. bisulcata, Mart. 



Calcareous nodules in soft shales from the same locality yielded the following 

 assemblage of organic remains, which indicate less purely marine conditions. 



Clisiophyllum, sp. 

 Lithostrotion irregulare, Phill. 

 Archceocidaris Urei, Flem. 

 Fenestclla, sp. 

 Athyris arnbigua, Sow. 



„ Roysii, Lev. 

 Gamarophoria crumcna, Mart. 

 Productus pundatus, Mart. 

 Spirifera lineata, Mart. 

 Syringothyris {Spirifera) cuspidata, Mart. 



Allorisma sulcata, Flem. 

 Aviculopecten ccelatus, M'Coy. 



Geikiei, Eth. M.S. 



„ inter stitialis, Phill. 



Edmondia sulcata, Phill. 

 Nihculana aitenuata, Flem. 

 Pteronites angustatus, M'Coy. 

 Sanguinolites roxburgcnsis, Hind. 



„ variabilis, M'Coy. 



Similar fossil-lists might be supplied from the limestones on this horizon in 

 Archer Beck and in the Esk. 



In the Kershope Burn, not far up stream from Kershopefoot, the lowest beds of 

 this group rest on the Glencartholm volcanic zone, where two coal-seams were formerly 

 wrought on the English side of the border. Again, in the upper part of Tweeden Burn 

 and its tributaries, south-east of New Castleton, there are sections showing outcrops of 

 coal-seams, some of which seem to have been formerly wrought, in association with 

 sediments that overlie the upper volcanic zone so well seen on the Fell top, near 

 Tweedenhead. These strata are evidently the continuation of those forming the 

 Lewis Burn Coal group just across the border. The limestones on this horizon in the 

 Tweeden Burn do not indicate such clear water-conditions as those of the Liddel, 

 Muir Burn, or Archerbeck, as shown by the fossils in the subjoined list. 



Lingula mytiloides, Sow. 



„ scruamiformis, Phill. 

 Oamaraphoria erumena, Mart. 

 Productus com, d'Orb. 

 Aviculopecten ccelatus, M'Coy. 



„ dissimilis, Phill. 



„ planicostatus, M'Coy. 



„ segregates, M'Coy. 



sp. 

 Edmondia unioniformis, Phill. 

 Entolium Sowerbyi, M'Coy. 



Leiopteria, sp. 



Naiadites (Myalina) crassa, Flem. 

 Nuculana attenuata, Flem. 

 Protoschizodus axiniformis, Portl. 

 Sedgwickia ovata, Hind. 

 Bellerophon hiulcus, Sow. 



„ decussatus, Flem. 



„ „ var. striatus, Flem. 



Euomphalus Dionysii, Goldf. 

 Loxonema constrictum, Sow. 

 „ cwvilincum, Phill. 



