C. LAP WORTH ON THE MOEEAT SERIES. 281 



the farmhouse of Mount Benger, once the residence of Hogg, the 

 Ettrick Shepherd. It occurs at the side of the high road between 

 the town of Inverleithen and the valley of the Yarrow, about half 

 a mile above the mouth of the burn. 



Here the greywackes of the country are exposed in several large 

 quarries in the hill- side, and with few local interruptions are seen 

 to dip steadily to the north-west at high angles. Where a small 

 fence crosses the burn, the highest beds of the dark- shale series 

 emerge from below them in a similar attitude. 



The first beds apparent are grey, green, and purple mudstones, in 

 which are intercalated two groups of black-shale bands, with seams 

 of white clay. They are much softer than usual, but otherwise 

 present all the peculiarities of the R.-maccimus zone of the Birkhill 

 Shales. The fossils they contain are beautifully preserved; the 

 characteristic forms Rastrites maximus, Monograptus Halli, and 

 Retiolites perlatus are especially abundant. 



Below the R.-maximus zone the talus obscures the section for 

 several yards, and the next strata visible are hard, black, slaty flags 

 of a couple of inches in thickness, barren of fossils except upon two 

 or three horizons. They are clearly a portion of the zone of Dicra- 

 nograptus CUngani of the Lower Hartfell Shales. In addition to 

 Dicranograptus ramosus and Dicellograptus Forchhammeri, Siphono- 

 treta micula (M'Coy) is perhaps their most abundant fossil. 



Beyond this point a badly exposed and greatly shattered section 

 marks the position of faulted beds. Next succeeds a group of soft, 

 slaty, black shales, containing in its higher portions several seams of 

 white mudstone, and recognizable at a glance as the zone of Pleuro- 

 graptus linearis. Its beds are almost flat, and are unbroken and 

 unmetamorphosed. They swarm with the characteristic fossils of 

 the zone, all of which are in excellent preservation. The most 

 striking species obtainable are Pleurograptus linearis (Carr.), Am- 

 phigraptus divergens (Hall), Dicellograptus elegans (Carr.), Biplo- 

 graptus quadrimueronatus (Hall). 



For the next hundred yards the stream flows over alluvium and 

 boulders, and the terminal beds of the section are met with at the 

 foot of a small rill which enters from the north. 



Here there is an exposure of the greater number of the zones 

 constituting the Birkhill- shale group. The deepest beds visible are 

 those of the upper portion of the D.-vesiculosus band, hard and flag- 

 like, and yielding Diplograptus vesiculosus (Mch.), Monograptus tenuis 

 (Portlock), &c. These are followed by the variegated beds of the 

 M.-gregarius zone, which, much faulted, and succeeded irregularly 

 above by the grey group of the Upper Birkhill Shales, with Mono- 

 graptus spimgerus, M. tenuis, &c, occupy the remainder of the 

 exposure, and pass below the greywackes to the south at an angle 

 of about 60°. 



ii. Eldinhope Burn (fig. 17).— On the opposite side of the Yarrow 

 a small section is visible in the burn of Eldinhope, about 200 yards 

 above the small cottage. On both sides of the exposure the grey- 

 wackes dip from off the Moffat beds at an angle of about 45° Of 

 Q. J. G. S. No. 134. 



