A SUMMER RAMBLE AMONG THE HEBRIDES. 109 



shale are swarded over, save where we here and there see 

 them laid bare in some abrupter acclivity or deeper water- 

 course. In the shale we find numerous minute Ammonites, 

 sorely weathered ; in the sandstone, Belemnites, some of them 

 of great size ; and dark carbonaceous markings, passing not 

 unfrequently into a glossy cubical coaL At the foot of the 

 cliff I picked up an ammonite of considerable size and well- 

 marked character, the Ammonites Murchisonce, first disco- 

 vered on this coast by Sir R Murchison about fifteen years ago. 

 It measures, when full grown, from six to seven inches in 

 diameter : the inner whorls, which are broadly visible, are 

 ribbed ; whereas the two, and sometimes the three outer ones, 

 are smooth, a marked characteristic of the species. My 

 specimen merely enabled me to examine the peculiarities of 

 the shell just a little more minutely than I could have done 

 in the pages of Sowerby ; for such was its state of decay, that 

 it fell to pieces in my hands. I had now come full in view 

 of the rocky island of Holm, when the altered appearance of 

 the heavens led me to deliberate, just as I was warming in 

 the work of exploration, whether, after all, it might not be 

 well to scale the cliffs, and strike directly on the inn. It 

 was nearly three o'clock ; the sky had been gradually dark- 

 ening since noon, as if one thin covering of gauze after an- 

 other had been drawn over it ; hill and island had first 

 dimmed and then disappeared in the landscape ; and now the 

 sun stood up right over the fast-contracting vista of the Sound, 

 round and lightless as the moon in a haze ; and the down- 

 ward cataract-like streaming of the gray vapour on the hori- 

 zon showed that there the rain had already broken, and was 

 descending in torrents. We had been thirsty in the hot sun, 

 and had found the springs few and scanty ; but the boy now 

 assured me, in very broken English, that we were to get a 

 great deal more water than would be good for us, and that 

 it might be advisable to get out of its way. And so, climb- 



