698 MK. J. E. MAEE AUB DK. H. A. IQCHOLSON 



wardian Museum have really been derived from one of the mud- 

 stone-bands of the SkelgiU Beds. 



The only section in the Skelgill Beds of the east side of Duddon 

 which is known to us occurs in Poaka Beck, just above Bridge End, 

 3 miles to the north of Dalton-in-Furness. The section seen there 

 is shown in fig. 11. 



Fig. 11. — Section at Poaka Beck, (Scale 12 feet to 1 inch.) 



^y.. 



Fault 

 Breccia. 



•A66? 



"^5^ 



A« 2 ?. The lowest beds seen are greatly disturbed, rusty-brown, 

 weathered shales, with many iU-preserved Graptolites, of which the 

 only one which we could determine was Climacograptus normalis, 

 Lapw. ; but from the general appearance of the shales we believe 

 them to belong to the zone of Dimorpliograptus confertus. 



Above these shales is a considerable fault-breccia and then a space 

 in which no rock is seen. 



A6 6 ?. Two feet four inches of blue mudstone, the Barren Band 

 or the summit of the Am-pyoo-aloniensis zone. 



Ac 1 ?. Yery dark ferruginous mudstones, 8 inches thick, with 

 few Graptolites. We obtained Monograptus distans, Portl., M. Nicoli, 

 Harkn., and Climacograptus normalis, Lapw. We believe this to 

 represent the M.-Clingani band, but did not see that fossil therein. 



Ac 2 ?. Pale green mudstone 1 foot thick. Either the Ampyx- 

 aloniensis zone or a pale band interstratified with the M.-spinigerus 

 shales. 



Ac 3. Banded black, grey, and pale mudstones, 2 feet 2 inches in 

 thickness, with abundance of Monograptus spinigerus, Mch., and 

 undoubtedly representing the M -spinigerus zone. 



Ac 4. Blue mudstones of the Acidaspis-erinaceus zone, of which 

 only the lowermost 6 feet are visible. At some distance above this 

 on the hiUside is a quarry in B, the pale shales of the BrowgiU 

 Beds, which here contain unusually large cubic crystals of pyrites 

 and many small undeterminable Brachiopods. There is little doubt 

 that the bed we have marked Ac 1 is really the M.-Clingani band, 

 otherwise the spinigerus-zone would be of unusual thickness here, 

 and we shall eventually point out that the beds tend to thin out in 

 this direction. 



The whole section is of little interest, and we call attention to it 

 as it is the most southerly exposure of the Stockdale Shales in the 

 Lake-district proper. 



