672 MR. J. E. MARK AITD DR. H. A. NICHOLSON- 



Thej'' are seen in many parts of the gill, immediately succeeding 

 the shales of the M.-convolutus zone. Eossils are rare, and the mud- 

 stones are of little interest. They have yielded : — 



Phyllopod spine. 

 , Whitfieldia tumida, Dalm. ? 



Leptsena quinquecostata, M'Coy. 



We shall speak of this hand as the Barren Band, 



To sum up the results obtained in our examination of the Middle 

 SkelgiU beds :— 



(i) The base is nowhere seen, owing to the strike-fault. 



(ii) The beds form the chief portion of the great cliff-section 

 which occurs on the left bank of the gill from the Upper Bridge to 

 the bottom of the wood. 



(iii) The beds are divisible into three zones of Graptolitic shales, 

 each topped by a zone of blue mudstones : — 



(1) A zone of black, pyritous, earthy, somewhat hard mudstones, 

 at least 7 feet thick, with Monograptus Jlmbriatus, Mch., M. gre- 

 garius^ Lapw., Rastrites peregrinus, Barr., Petalograptus ovato-elonga- 

 ttis, Kurck, and Dawsonia canipanulata, Nich., &c. : = Monograptus- 



fimhriatus zone. 



(2) A zone of hard, blue, bedded mudstones, 5 feet thick, with 

 bands of calcareous nodules, containing Encrinurus punctatus, Wahl., 

 &c. : = Encrinurus-punctatus zone. 



(3) A thin band of black mudstones, only 8 inches, with Mono- 

 graptus argenteus, Nich., M. gregarius, Lapw., and a host of other 

 fossils : ■:= Monograptus-argenteus zone. 



(4.) A zone of hard, blue, bedded mudstones, 12 feet in thickness, 

 with many calcareous nodules towards the centre, and containing many 

 Trilobites, including Phacops elegans, var. nov. glaher: =Phacops- 

 glaher zone. 



(5) A thick zone of laminated, dark, greyish-blue Graptolitic shales, 

 with olive-brown stains on the joint-faces, having several green 

 streaks throughout and thick deposits of mudstones near the top 

 and base, the whole attaining a thickness of 7 feet 9 inches, and 

 containing Monograptus convolutus, His., Monograptus gregarius, 

 Lapw., and many other Graptolites : = Monograptus-convolutus zone. 



(6) A zone of blue mudstones, 4 feet thick, and containing few 

 fossils : = Barren Band. 



Ac. Upper Skelgill Beds. 



(1) The Graptolite-shales which succeed the highest beds of the 

 Middle Skelgill group are only one foot thick. They consist of very 

 fissile laminated shales, sometimes black and very ferruginous, and 

 at other times of a lighter colour. They are seen near the Lower 

 Bridge near the summit of the footpath, where they contain a con- 

 siderable number of fossils. Other and more highly fossiliferous 

 exposures of this band occur at several points above the Lower 

 Bridge, on the moorland portion of the stream. The fossils serve to 

 connect them with a succeeding band of Graptolitic shales, and they 

 themselves contain no characteristic form. Their fossils are : — 



