88 
yellow tint, as if coloured by oxide of iron ; it runs nearly 
at right angles to the bedding of the stone, and appears as 
if standing in the same position as it had grown. The 
stone is a rolled one but it is evidently from the Manx 
schists found in the vicinity. These, according to Professors 
Harkness and Nicholson, are of the age of the Skiddaw 
slates, but the rock in which the fossil occurs may be of 
older date, as some of the lower portions of the series have 
not yet been clearly determined ; so here we have evidence 
of a plant in the lowest part of the Silurian formation, or 
even lower. By diligent search, the rock in which the 
specimen occurs may probably be found in situ in the upper 
part of the Laxey valley. The great resemblance, if not 
identity, of the Manx with the American specimen is very 
remarkable, and shews the similarity of conditions then 
prevailing in distant parts of the globe. The specimen 
might have been called Psilophytum cornutum, if any 
marking on the surface of the stem had been observed, but 
as these appear to be absent it is proposed to call it Psilo- 
phytum Monense . As to the nature of the water in which 
it grew there is no evidence from organic remains, but its 
characters resemble those of a fucoid more than a land 
plant. 
<£ On Ptolemy’s Geography, with reference to the Coast 
from Caernarvon to Cumberland,” by Thomas Glazebrogk 
Rylands, Esq. Communicated by Dr. R. Angus Smith, 
FR.S, &c. 
(The author said, This paper was prepared as “ A Chip 
from my Workshop,” at the request of a friend who knew 
that I had been engaged for some years investigating 
Ptolemy’s Geography.) 
The special subject of it was selected because it was on 
the one hand a bit of coast in the far north-west of 
Ptolemy’s habitable world, respecting which he had no 
unusual information or interest. It therefore supplies a 
fair test of his accuracy. On the other hand it is the por- 
tion of coast best known to ourselves, and it has been the 
subject of considerable discussion. 
