ON EXCAVATIONS IN THE PALEOZOIC HOCKS Or WALES, &C. 211 



liear the south" fence of the Dairy Hill field in order to ascertain the 

 dip of the beds. 



It showed the following vertical section of beds lying nearly 

 horizontally ; — 



Ft. In. 



a. A coarse somewhat conglomeratic bed of grit or sandstone witli 



rusty coloured blotches and greenish earthy patches . . .5 



b. Micaceous green flaggy sandstone 4 



c. ,, „ but more compact and rather coarser . . .09 



d. Micaceous sandstone with rusty spots ; cf. beds / of Excavation 



No. 1. Base not seen 2 



The general aspect of these beds recalls those found below the 

 Olenellus Limestone of the Comley Quarry. 



Nos. 13, 14, 15, 16, were sunk on the northern slopes of Hill 

 House Ridge to ascertain the nature of the shales there apparently 

 overlying the Hill House Grits, and to localise the exact position of a 

 fault mapped by Professor Lapworth. 



No. 13, near the Comley Brook, exhibits beds of grit and shale dipping 

 to the south-west at about 45°. 



Nos. 14, 15, 16, showed shales often gritty and micaceous with 

 included bands of harder shale and grit, all with a nearly vertical dip 

 and a north and south strike. 



It is clear that the fault in question lies between Nos. 13 and 14. 



Results. 



Previous to the time when these excavations were commenced it was 

 well known to geologists that in the Comley area the Wrekin Quartzite 

 underlay the Comley Sandstone Series ; that in this Sandstone series 

 occurred a fossiliferous group of strata of no great vertical thickness, 

 whicli was partly exposed in the Comley Quarry ; and also that the 

 lower beds of this Quarry group yielded the Oletiellus fauna and its 

 higher beds, Pai-adoxides ; but the precise line of stratigraphlcal demarca- 

 tion between the two sets of strata yielding the older fauna and those 

 yielding the younger fauna, even within this little fossiliferous group, 

 remained undetermined. And, although it was known that both above and 

 below the beds exposed in the quarry there occurred a comparatively great 

 thickness of strata belonging to the local Comley Sandstone Series, that 

 series remained undivided owing to the paucity of natural sections. 



The results of these excavations enable us for the first time to fix 

 almost exactly the local stratigraphical line of division between the Lower 

 and Upper Comley Series, and to give details as to the sequence and 

 characteristics of the various lithological bands in the fossil-bearing 

 group for some distance above and below that line, and thus permit of 

 the fixation of the true stratigraphical horizons of the fossils which have 

 been at various times collected from these beds, or from loose fragments 

 derived from them. 



Again, although it cannot be claimed that these excavations have 

 furnished a sufficiency of evidence to enable geologists to distinguish all the 

 local members of the Comley Sandstone Series, they have supplied a large 

 amount of additional testimony in support of the vie«' that not only is the 

 series as a whole separable into two main divisions — an upper and a lower 

 series distinguishable by their fossils — but that each of the two divisions 



1908. K 



