C. LAP WORTH ON THE MOFFAT SERIES. 



261 



disturbed patches we detect the following species : — Monograptus 

 spinigerus (Nich.), M. Halli, Rastrites distans (Lapw.), and M. Iiisin- 

 geri (Carr.), all of which are strictly peculiar to the grey group or 

 Upper Birkhill Shales of Dobb's Linn. 



Fig. 2. — Craigmichan Scaurs. (Lower Section.) 



Selcoth Burn 



/ r 



I). Flagstones and greywackes of the Gala group. 

 Cb. Grey shales with black and white seams, contorted. Rastrites maximus, 



Monograptus spinigerus, Diplograptus cometa, &c. 

 Ca. Black carbonaceous flags and shales, with Rastrites per egrinus, Monograptus 



gregarius, Diplograptus vesiculosus, &c. 

 Bb. Pale mudstones and shales, non-fossiliferous. 



In the beds immediately below no fossils are visible ; but if we 

 examine them in their extension higher up the stream, we see that 

 they include the coloured lines of the M. -gregarius bands, together 

 with some of the hard flag-like beds of the D.-vesiculosus zone ; and 

 yield in abundance such characteristic forms as D. vesiculosus (ISTich.), 

 D. tamariscus (Nich.), D. palmeus (Barr.), M. gregarius (Lapw.), 

 Rast?'ites peregrinus (Barr.), &c. 



This completes the section of the southern cliff. Crossing the 

 bed of the stream and commencing the ascent of the northern slope, 

 we pass over a great group of barren shales and mudstones of a 

 greyish-brown colour, clearly the " Barren Mudstone " of our typical 

 section, here, however, showing no trace of the fossiliferous D.-anceps 

 seams. They are apparently nearly a hundred feet in thickness, 

 more than twice that of their prototypes of Dobb's Linn. The 

 cause of this is soon evident, as they are seen to be arranged in a 

 sharp anticline, the axis of which is inverted, dipping slightly to the 

 north-west. 



To the Barren Mudstone succeeds a great mass of the Lower Birkhill 

 Shales, much broken and twisted. It reposes upon the preceding 

 zone at a low angle, exhibits the peculiar variegated mudstone 

 lines, and yields an abundance of characteristic fossils. It subsides 



