UPPEK OLD RED SANDSTONE. 
441 
Fig. 494. 
Fisv. 495. 
Fig. 49G. 
Old Red Sandstone and by 
one only in the Carbonifer¬ 
ous group), and Glytolepis 
and Asterolepis^ both exclu¬ 
sively confined to the “ Old 
Red.” In the same Irish 
sandstone at Kiltorkan has 
been found an A 7 lodonta or Anodonta Jukemi,¥ov\iQs. Upper Devonianf 
n ^ ^ 1 i. 1 , 1 Kiltorkan, Ireland.' 
fresh-water mussel, the only 
shell hitherto discovered in the Old Red Sandstone of th( 
British Isles (see Fig. 494). In the same formation an 
found the fern (Fig. 496) and the Lepi\ 
dode7idro7i (Fig. 495), and other specie 
of plants, some of which. Professor Heef 
remarks, agree specifically with sj)eci( 
from the lower carboniferous beds. Thi 
induces him to lean to 
the opinion long ago ad¬ 
vocated by Sir Richard 
Griffiths, that the yellow 
sandstone, in spite of its 
fish remains, should be 
classed as Lower Carbon¬ 
iferous, an opinion which 
I am not yet prepared 
to adopt. Between the 
Biongn. Upper Devo- Mountain Limestone and 
man, Kilkenny. Sandstone in 
the south-west of Ireland there intervenes 
a formation no less than 5000 feet thick, 
called the “ Carboniferous slate,” and at the 
base of this, in some places, are local depos- 
its, such as the Glengariff Grits, which ap- 
pear to be beds of passage between the Car- Schimp. (CycUpteHs 
boniferous and Old Red Sandstone groups. fSHaSSl 
It is a remarkable result of the recent ex- R<>P:)* 
amination of the fossil flora of Bear Island, 
latitude V4° 30' N., that Professor Heer has described as 
occurring in that part of the Arctic region (nearly/twen¬ 
ty-six degrees to the north of the Irish locality) ^ flora 
agreeing in several of its sjDCcies with that of the yellow 
sandstones of Ireland. This Bear Island flora is beliewed by 
Professor Heer to comprise species of plants some of which 
ascend even to the higher stages of the European Carbonif¬ 
erous formation, or as high as the Mountain Limestone and 
Millstone Grit. Palaeontologists have long maintained that 
19 - 
