THE OLD RED SANDSTONE. 107 
and debris, nor could I trace their relation to a single known 
rock. I was struck, as I well might, by the utter strangeness 
of the forms—the oar-like arms of the Pterichthys and its 
tortoise-like plates—the strange, buckler-looking head of 
the Coccosteus, which, I suppose, might possibly be the back 
of a small tortoise, though the tubercles reminded me rather 
of the skin of the shark — the polished scales and plates of 
the Osteolepis —the spined and scaled fins of the Cheiracan- 
thus —above all, the one-sided tail of at least eight out of 
the ten or twelve varieties of fossil which the deposit con- 
tained. All together excited and astonished me. But some 
time elapsed ere I[ learned to distinguish the nicer generic dif- 
ferences of the various organisms of the formation. I found 
fragments of the Pterichthys on this morning; but I date its 
discovery, in relation to the mind of the discoverer, more than 
a twelvemonth later.* I confounded the Cheiracanthus, too, 
with its single-spined, membranous dorsal, with Diplacanthus 
ichthyolite, furnished with two such dorsals ; and the Diplop- 
terus with the Osteolepis. Still, however, I saw enough to 
* T find, by some notes, which had escaped my notice when draw- 
ing up for the Witness newspaper the sketches now expanded into a 
volume, that in the year 1834 I furnished the collection of a geologi- 
cal friend, the Rey. John Swanson, minister of the parish of Small 
Isles, in the Outer Hebrides, with a well-marked specimen of the 
Pterichthys Millerit. The circumstance pleasingly reminds me of the 
first of all my early acquaintance, who learned to deem the time not 
dly squandered that was spent in exploring the wonders of bygone 
creations. Does the minister of Small Isles still remember the boy 
who led him in quest of petrifactions — himself a little boy at the 
time—to a deep, solitary cave on the Moray Frith, where they 
lingered amidst stalactites and mosses till the wild sea had surround- 
ed them unmarked, barring all chance of retreat, and the dark night 
came on? 
