292 RAMBLES OF A GEOLOGIST. 



shire specimens portrayed by Agassiz in his great work ; and 

 beside it, one of the two specimens of Pterichthys oblongus 

 which he figures, and on which he establishes the species. The 

 other individual, a Cromarty specimen, graces my little 

 collection. The gloomy day passed pleasantly in decipher- 

 ing, with so accomplished a geologist as Mr Duff, these curious 

 hieroglyphics of the old world, that tell such wonderful stories, 

 and in comparing viva voce, as we were wont to do long years 

 before in lengthy epistles, our respective notions regarding 

 the true key for laying open their more occult meanings. And, 

 after sharing with him in his family dinner, I again took my 

 seat on the mail, as a chill, raw evening was falling, and rode 

 on, some six or eight and twenty miles, to Campbelton. The 

 rain pattered drearily through the night on my bed-room win- 

 dow ; and as frequent exposure to the wet had begun to tell 

 on a constitution not altogether so strong as it had once been, 

 I awakened oftener than was quite comfortable, to hear it 

 The morning, however, was dry, though gray and sunless ; 

 and, taking an early breakfast at the inn, I traversed the flat 

 gravelly points of Ardersier and Fortrose, that, projecting 

 like moles far into the Frith, narrow the intervening ferry 

 to considerably less than one-third the width which it would 

 present were they away. The origin of these long detrital 

 promontories, which form, when viewed from the heights on 

 either side, so peculiar a feature in the landscape, and which, 

 were they directly opposite, instead of being set down a mile 

 awry, would shut up the opening altogether, has not yet been 

 satisfactorily accounted for. One special theory assigns their 

 formation to the agency of the descending tide, striking in 

 zig-gig style, in consequence of some peculiarity of the coast- 

 line or of the bottom, from side to side of the Frith, and de- 

 positing a long trail of sand and gravel, at nearly right angles 

 with the beach, first on the one shore and then on the other. 

 But why the tide, which runs in various zig-zag crossings in 



