A SUMMER RAMBLE AMONG THE HEBRIDES. 77 



as is frequently the case, seem indestructible, while the hard 

 matrix in which they are embedded has weathered from 

 around them. Some of the scales present the rhomboidal 

 outline, and closely resemble those of the Lepidotus Minor 

 of the Weald ; others approximate in shape to an isosceles 

 triangle. The teeth are of various forms : some of them, evi- 

 dently palatal, are mere blunted protuberances glittering with 

 enamel, some of them present the usual slim, thorn-like 

 type common in the teeth of the existing fish of our coasts, 

 some again are squat and angular, and rest on rectilinear 

 bases, prolonged considerably on each side of the body of the 

 tooth, like the rim of a hat or the flat head of a scupper nail. 

 Of the occipital plates, some present a smooth enamelled 

 surface, while some are thickly tuberculated, each tubercle 

 bearing a minute depression in its apex, like a crater on the 

 summit of a rounded hill. We find reptilian bones in abun- 

 dance, a thing new to Scotch geology, and in a state of 

 keeping peculiarly fine. They not a little puzzled John 

 Stewart : he could not resist the evidence of his senses : they 

 were bones, he said, real bones, there could be no doubt of 

 that : there were the joints of a back-bone, with the hole the 

 brain-marrow had passed through ; and there were shank- 

 bones and ribs, and fishes' teeth ; but how, he wondered, had 

 they all got into the very heart of the hard red stones ? He 

 had seen what was called wood, he said, dug out of the side 

 of the Scuir, without being quite certain whether it was wood 

 or no ; but there could be no uncertainty here. I laid open 

 numerous vertebrae of various forms, some with long spi- 

 nous processes rising over the body or centrum of the bone, 

 which I found in every instance, unlike that of the Ichthyo- 

 saurus, only moderately concave on the articulating iaces; 

 in others the spinous process seemed altogether wanting. 

 Only two of the number bore any mark of the suture which 

 unites, in most reptiles, the annular process to the centrum : 



