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58 NOTES ON THE 
swelling hills of no great elevation, formed chiefly of uplifted 
Silurian slates. The latter are probably the oldest fossiliferous 
rocks in Scotland, and are characterized by many species of the 
Graptolitic family of zoophytes. Some of these contain carbo- 
naceous impressions which appear to be those of fucoids, the ear- 
liest vegetable inhabitants of the primeval sea ; many of the schists 
are ‘highly impregnated with carbonaceous matter, which has 
probably been derived from the decay of the delicate cellular 
tissue of countless seaweeds which carpeted the floor of the an- 
cient ocean. It is of extreme interest to note in this district 
the first dawn of animal and vegetable life (in the shape of zoo- 
phytes and alge) in ancient Scotland. The geological character 
of these rocks has been fully examined and described by Pro-. 
fessor Harkness, of Cork, who last summer was fortunate enough 
to discover, in Glenkiln burn, some new and very interesting 
algoid impressions in the graptolitic schists. The uplifting of 
the strata, and subsequent denudations and disturbances, have 
produced several characteristic appearances in the physical geo- 
graphy of the country. Some hills of Silurian range are pecu- 
harly formed, so as to be distinguishable at a distance from those 
of trap, with which they are here and there intermingled; and 
are intersected by rugged ravines. Beyond this district the Silu- 
rian rocks constitute the lead hills, the Moffat range, and the 
general range of the Lammermuirs; at certain points they are 
penetrated by rich metalliferous veins, yielding lead, silver, cop- 
per, and other ores. The hills are mostly rounded, destitute of 
trees, bare and unpicturesque; some of them rise to a consi- 
derable height. In the higher points of this range are some of 
the rarer alpines, e. g. Woodsia, near Moffat. The sides of the 
Dumfries basin are also partially formed by outbursts of trap 
and other rocks, e.g. Criffel, a mountain guarding the embou- 
chure of the Nith. To a geological eye these trap hills are dis- 
tinguishable at a great distance from those formed of Silurian 
strata. The “new red” of this district is well known to contain 
valuable specimens of reptilian footmarks and ripple and rain 
marks on the shore sand of the ancient ocean. A considerable 
amount of iron occurs here and there in the soil, and there are 
several chalybeate springs, of which the “ Brow Well” is a local 
celebrity. The soil for the most part is sandy and porous. Over- 
lying the sandstone are considerable beds of diluvial boulder clay, 
