C. LAPWORTH ON THE MOFFAT SERIES, 



279 



stones, red, yellow, and blue, afford- 

 ing in its lower portion Monograp- 

 tus gregarius (Lapw.), M. cyphus, 

 (Lapw.), &c, and in its higher beds 

 JRastrites peregrinus (Barr.), Mono- 

 graptus communis, &c. 



The foregoing strata dip to the 

 south at 45°-60°, and near the 

 foot of the stream the succession 

 is closed by a group of grey and 

 black shales with white lines, 

 clearly the Upper Birkhill beds, 

 which pass beneath the grey wackes 

 of the district to the south. 



Shiel Syhe. — A small and indif- 

 ferent section on the opposite side 

 of the hollow to the south-west 

 affords evidence of a further con- 

 traction of the band. It exhibits 

 merely a few feet of the D.-vesi- 

 culosus zone and a portion of the 

 highest Grey-Shale group, dipping 

 to the north — enough, however, to 

 prove the presence of the Birkhill 

 shales to the north of the axis of 

 the band. 



Cossar-Hill Bum. — In C'ossar- 

 Hill Burn a few shattered and 

 highly indurated black beds are all 

 that remain to represent the Berry- 

 bush band, and in the next valley 

 it seems altogether to disappear 

 below the contorted greywackes. 



Summary. 



At this stage, therefore, our 

 study of the strata exposed in the 

 four uninterrupted black-shale 

 bands to the south-west of St. 

 Mary's Loch has established the 

 following propositions : — 



(i.) The sequence, lithological 

 characters, and peculiar fossils of 

 the subgroups of strata included 

 within these bands are identical 

 in every respect with those of the 

 various zones of the Moffat series 

 as exposed in our typical section 

 at Dobb's Linn. 



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