80 THE CRUISE OF THE BETSEY ; OR, 



reptiles, the Plesiosaurus was the most extraordinary. An 

 English geologist has described it, grotesquely enough, and 

 yet most happily, as a snake threaded through a tortoise. And 

 here, on this very spot, must these monstrous dragons have 

 disported and fed ; here must they have raised their little rep- 

 tile heads and long swan-like necks over the surface, to watch 

 an antagonist or select a victim ; here must they have warred 

 and wedded, and pursued all the various instincts of their 

 unknown natures. A strange story, surely, considering it is 

 a true one ! I may mention in the passing, that some of the 

 fragments of the shale in which the remains are embedded 

 have been baked by the intense heat into an exceedingly hard, 

 dark-coloured stone, somewhat resembling basalt. I must 

 add further, that I by no means determine the rock with 

 which we find it associated to be in reality an altered sand- 

 stone. Such is the appearance which it presents where wea- 

 thered ; but its general aspect is that of a porphyritic trap. 

 Be it what it may, the fact is not at all affected, that the 

 shores, wherever it occurs on this tract of insular coast, are 

 strewed with reptilian remains of the Oolite. 



The day passed pleasantly in the work of exploration and 

 discovery ; the sun had already declined far in the west ; and, 

 bearing with us our better fossils, we set out, on our return, 

 by the opposite route to that along the Bay of Laig, which 

 we had now thrice walked over. The grassy talus so often 

 mentioned continues to run on the eastern side of the island 

 for about six miles, between the sea and the inaccessible ram- 

 part of precipice behind. It varies in breadth from about 

 two to four hundred yards ; the rampart rises over it from 

 three to five hundred feet ; and a noble expanse of sea, closed 

 in the distance by a still nobler curtain of blue hills, spreads 

 away from its base : and it was along this grassy talus that 

 our homeward road lay. Let the Edinburgh reader imagine 

 the fine walk under Salisbury Crags lengthened some twenty> 



