GNEISS, MICA SCHIST, AND SLATE SYSTEMS. 



665 



whose sides are quite mural, and form the most magnificent amphitheatre in nature. The 

 Wyddfa is on one side ; Crib y Distill, with its serrated tops, on another ; Crib Cock, a 

 ridge of fiery redness, appears beneath the preceding ; and opposite to it is the boundary 

 called Lliwedd. Another very singular support to this mountain is Y Clawdd Coch, 

 rising into a sharp ridge, so narrow as not to afford breadth even for a path." 



Pennant proceeds to remark : " The view from this exalted scene is unbounded. In 

 a former tour I saw from it the county of Chester, the high hills of Yorkshire, part of 

 the north of England, Scotland, and Ireland ; a plain view of the Isle of Man ; and that of 

 Anglesey lay extended like a map beneath us, with every rill visible. I took much pains 

 to see this prospect to advantage ; sat up at a farm on the west till about twelve, and 

 walked up the whole way. The night was remarkably fine and starry ; towards morn the 

 stars faded away, and left a short interval of darkness, which was soon dispersed by the 

 dawn of day. The body of the sun appeared most distinct, with the rotundity of the 

 moon, before it rose high enough to render its beams too brilliant for our sight. The sea, 

 which bounded the western part, was gilded by its beams, first in slender streaks, at length 

 glowing with redness. The prospect was disclosed to us like the gradual drawing up of a 

 curtain in an amphitheatre. We saw more and more, till the heat became so powerful as 

 to attract the mists from the various lakes, which in a slight degree obscured the prospect. 

 The shadow of the mountain was flung many miles, and showed its bi-capitated form ; the 

 Wyddfa making one, Crib y Distill the other. I counted this time between twenty and 

 thirty lakes, either in this county, or Meirionydd (Merioneth) shire. The day proved so 

 excessively hot, that my journey cost me the skin of the lower part of my face before 

 I reached the resting-place, after the fatigue of the morning. 



" On this day the sky was obscured very soon after I got up. A vast mist enveloped 

 the whole circuit of the mountain. The prospect down was horrible. It gave the idea of 

 a number of abysses, concealed by a thick smoke, furiously circulating around us. Very 

 often a gust of wind formed an opening in the clouds, which gave a fine and distinct vista 

 of lake and valley. Sometimes they opened only in one place ; at others in many at once, 

 exhibiting a most strange and perplexing sight of water, fields, rocks, or chasms in fifty 

 different places. They then closed at once, and left us involved in darkness ; in a small 



space they would separate again, and 

 fly in wild eddies round the middle of 

 the mountains, and expose, in parts, 

 both tops and bases clear to our 

 view." 



But Snowdon the Saxon trans- 

 lation of the Welsh for snow-moun- 

 tain with the ranges in connexion 

 with it, acquires peculiar interest, 

 from its presenting us with the dawn 

 of organic life in the world which we 

 inhabit, as far as extant monuments 

 serve to unfold it the morning twi- 

 light of the era of living beings, 

 which broke immeasurable ages be- 

 fore the present epoch. Professor Phillips speaks of having found, himself, in the slates 

 of Snowdon, Zoophyta (lamelliferous corals) and Brachiopodous (arm-feet) bivalves. The 

 latter are mollusca, so called from having two long, spiral, fleshy arms, or brachia. 

 The above specimens he obtained from Snowdon in the year 1836. 



" It may surprise," he observes, " the speculators in cosmogony to hear that these* the 



FOSSILS FHOM SNOWDON, 1836. 



Fig. 1. Cyathophyllum. 



2. Cyathophyllum, the same as found in the Silurian system. 



3. Terebratula distinct from T. prisca. 



4. Spirifera with knotted ridges. 

 6. Producta (or Leptaana). 



6. Terebratulai 



7. Spirifera with fine radiating striae. 



8. Leptaena L. lata of the Silurian rocks. 



