44 GEOLOGY OF SHROPSHIRE. 
as previously shown, dips away from volcanic bosses at the most varied 
dips and strikes. 
(c.) Precambrian.—On the rejection of hypotheses a and b, the 
balance of probability is decidedly in favour of this supposition. 
4.—TueE Fauna or THE QUARTZITE. 
For years I searched for fossils in vain; but recently I detected on 
the south-east flank of the Wrekin, near the cottage, one good specimen 
of a worm-burrow, apparently Arenicolites, and portions of one or two 
more. -The burrow is a simple loop, resembling a letter U, 2 inches in 
length by linch in breadth. I have proposed for it the name Arenicolites 
uriconiensis. If my view of the age of the quartzite is correct, this 
specimen is, with the exception of the problematical Hozoon, the oldest 
known fossil. 
B. Tue Quarrzite or THE StTrPER STONES. 
The physical characters of this rock have been so well described by 
Murchison (‘‘ Siluria,” chap. iii.,) that it will be unnecessary to make 
additional observations. I have but to add a suggestion on its geological 
age. By the author of ‘“‘Siluria” it is placed on the horizon of the 
Lingula Flags, on the ground that it is below the Llandeilo, and contains 
worm-burrows and fragments of a Lingulid, which, it is candidly stated, 
does not resemble Lingulella Davisii. Geologists of the present day will 
hardly be disposed to accept such evidence as conclusive. The shales 
overlying the quartz rock contain Illenus perovalis, Calymene parvifrons, 
Aiglina, Placoparia, and other Arenig forms. There can, therefore, be 
little doubt that the quartzite is of Arenig age, and, consequently, quite 
distinct from the quartzite of the Wrekin area. This view is confirmed 
by my recent discovery of the Shineton Shales (Tremadoc) in the valley 
to the east of the Stiper Stones. The two rocks can generally be 
distinguished from each other even in hand specimens; and, when they 
are conglomeratic, the pebbles of the Arenig quartzite mainly consist of 
quartz, while the included fragments of the Wrekin quartz rock are 
felsitic. 
THE FERNS OF NORTHANTS. 
BY G. C. DRUCE. 
As might be expected from the geological and physical character of 
the county, Northamptonshire is very poor in ferns, only those with a 
large comital distribution occurring, and then but in few numbers, in 
widely separated localities; driven by cultivation to take refuge in some 
shady spinney or damp hedgerow, and most frequently to be found on 
the western side of the county, where they are favoured with more 
congenial soil and a larger rainfall than the Ceterach and Ruta-muraria 
of the eastern portion of the county. Indeed, so infrequent are the 
ferns that many inhabitants of the district are dubious about the 
occurrence of such universally distributed ones as Filix-femina and 
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