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MR. J. E. MAEK Al^D DE. H. A. NICHOLSON 



The nodules are again well exhibited in the cliff at the bottom of 

 the moorland portion of the gill, just before the stream enters the 

 wood, and in many places between this and the Upper Bridge. At 

 one point, however, where the cliflP attains a great height, and has 

 a concave curve produced by a loop of the stream, these beds are 

 faulted out, and a higher set of mudstones is brought down against 

 the strike-fault, which here runs in the bed of the stream. 



The fossils of the mudstones which we have been describing are 

 procurable with some difficulty, owing to the hardness of the rock. 

 They are not often found on the bedding-planes, which usually pre- 

 sent wrinkled surfaces, so that the rock must be broken across in 

 order to obtain the well-preserved fossils. We have found : — 



Encrinurus punctatus, Wahl., var. 



arenaceixs, Salt. 

 Acidaspis. 



Leptisna quinquecostata, M'Coy. 

 Orthoceras araneosum, Barr. 



The Encrimirus is a tolerably common fossil, and we have not 

 hitherto met with it in any of the other deposits in this gill, so we 

 use it to mark this zone, which we consequently name the Zoyie of 

 Encrinurus punctatus, Wahl. 



(3) Above this zone comes a band of small thickness, but of 

 great interest, owing to the varied assortment of fossils which it 

 contains. It occurs right in the centre of the Middle Skelgill beds, 

 and is succeeded by mudstones of a similar lithological character to 

 those which lie below it, and passes up into them in the same 

 manner. The lower portion of these upper mudstones, similarly to 

 the upper portion of the lower group, consists of light-coloured, shaly 

 layers, and between these two we find eight inches of extremely 

 black shales, somewhat similar to those of th.eM.-Jlmhriatus Zone, but 

 even harder, and containing Graptolites in an exquisite state of relief. 

 About three inches from the summit of this bed is a pale-green 

 streak in which Graptolites are extremely rare, and which is remark- 

 able for its extraordinary persistence. The bed is seen by the path 

 which crosses the Lower Bridge, and may be traced passing along 

 the face of the cliff to the dip-fault which occurs a few yards above the 

 bridge. It is here thrown down, and occurs in the great precipice 

 between the two dip-faults, at a height of a foot or two above the 

 stream. It is marked all the way from the path to the north-east 

 end of this cliff by a furrow caused by our removal of the shales, 

 so that it is now extremely difficult to get satisfactory specimens at 

 this spot. The same bed may be found at one or two points below 

 the Lower Bridge, but in many places, both here and above the 

 bridge, the deposit is inaccessible. Along a great part of the cliff 

 below the Upper Bridge the band is found to be crushed out, and 

 the mudstones above are brought into contact with those below ; but 

 on tracing the line of junction the thin band gradually appears, at 

 first much crushed, but further away from the point of maximum 

 disturbance it is in its normal condition. At the point of maximum 

 throw of the principal strike-fault of the stream the beds are absent 



