18G8.] HA.RKNESS AND NICHOLSON CONISTON GROUP. 299 



abundance of OrtJioceras primcevum and 0. sahuyidalatum, forms 

 which range from the Caradoc or Bala rocks upwards to the Wen- 

 lock. 



On the eastern side of Windermere, near Low Wood, in the 

 course of a small stream flowing from Wansfell, and called Skelgill, 

 a section is obtained similar to that of Arnco-side Beck, the Conis- 

 ton limestone and the beds which support it being well seen here, 

 and also the rocks succeeding the Coniston limestone. The course 

 of this stream, like Arnco-side Beck, is nearly in the line of the 

 strike of the strata ; and immediately above the Coniston limestone 

 the same black mudstones occur, with a profusion of Graptolites, 

 similar to those of Arnco-side Beck. 



Some portion of these graptolitiferous beds are highly anthracitic, 

 and both here and at Arnco-side Beck the rocks have a great litho- 

 logical resemblance to the graptoliferous shales of Dumfriesshire. 

 These graptolitiferous mudstones also pass upwards into grey grits, as 

 at Arnco-side Beck ; but in Skelgill there are fewer shales interstra- 

 tified in the lower parts of the grey grits. In Skelgill the Graptolites 

 are often in relief, being in the state of iron pyrites, while in Arnco- 

 side Beck they occur usually as grey stains upon the mudstones. 



At Skelgill by far the most abundant form is Dlplograpsus teretius- 

 culus, while at Arnco-side Beck no species can be said to be most 

 predominant. 



The following are the species of Graptolites which occur in the 

 mudstone either in Long Sleddale or at Skelgill : — 



1. Diplograpsus teretiusculus, Hlsing. 13. G. lobiferus, M'-Coy. 



2. D. ang.ustifolius, Hall. 14. Gr. Nilssoni, Barr. 



3. D. confertus, Nick., n. s. 15. G-. priodon, Bronn. 



4. D, folium, Hising. 16. G. Sagittarius, Linn. 



5. D. palmeus, Barr. 17. G. Sedgwickii, PortlocJc. 



6. D. putillus, Hall. 18. „ (var. triangulatus), 



7. D. pristis, Hising. HarJcness. 



8. D. tamariscus, Nich., n. s. 19. G. tenuis, PortlocJc^ 



9. D. vesieulosus, Nich., n. s. 20, G. turriculatus, Barr. 



10. Graptolites Boheraicus, Barr. 21. Eastrites Linnai, Barr. 



11. G. discretus, iV7cA., n. s. 22. R. peregrinus, Barr. 



12. G. fimbriatus, Nich., n. s. 23. Retiolites perlatus, Nich., n. s. 



— a very rich graptolite fauna, with which occur at Skelgill two 

 Coniston-limestone fossils (SpJiceronites punctatus and Orthis calli- 

 gramma) and OrtJioceras primcevum'^ 



Between Windermere and Coniston there are no exposures of the 

 graptolitiferous mudstones, and there is an absence of sections showing 

 them in the country south-west of Coniston — although the Coniston 

 limestone and the harder rocks of the Coniston-flag series are well 

 seen, especially west of the village of Torver. 



The graptolitiferous mudstones being comparatively soft, their 

 occurrence often gives rise to a narrow hollow immediately south-east 

 of the Coniston-limestone band. Where this hollow is intersected by 

 streams, gravel usually forms their beds, and the rocks on the sides 

 are covered by soil. This is the case in Torver Beck, where the 

 Coniston limestone is well exposed, and where the grey grits over- 



