BAUBLES OF A GEOLOGIST. 23-5 



mens of the Inoceramus, a thin-shelled, ponderously-hinged 

 conchifer, characteristic of the Cretaceous group, but which 

 has no living representative ; with numerous flints, traversed 

 by rough-edged, bifurcated hollows, in which branched sponges 

 had once lain ; a well-preserved Pecten ; the impressions of 

 spines of Echini of at least two distinct species ; and the nicely- 

 marked impression of part of a Cidaris, with the balls on which 

 the sockets of the club-like spines had been fitted existing in 

 the print as spherical moulds, in which shot might be cast, 

 and with the central ligamentary depression, which in the 

 actual fossil exists but as a minute cavity, projecting into the 

 centre of each hollow sphere, like the wooden fusee into the 

 centre of a bomb-shelL This latter cast, fine and sharp as 

 that of a medal taken in sulphur, seems sufficient of itself to 

 establish two distinct points : in the first place, that the sili- 

 ceous matter of which the flint is composed, though now so 

 hard and rigid, must, in its original condition, have been as 

 impressible as wax softened to receive the stamp of the seal ; 

 and, in the next, that though it was thus yielding in its cha- 

 racter, it could not have greatly shrunk in the process of hard- 

 ening. I looked with no little interest on these remains of 

 a Scotch formation now so entirely broken up, that, like those 

 ruined cities of the East which exist but as mere lines of 

 wrought material barring the face of the desert, there has 

 not " been left one stone of it upon another /' but of which 

 the fragments, though widely scattered, bear imprinted upon 

 them, like the stamped bricks of Babylon, the story of its 

 original condition, and a record of its founders. All Mr 

 Longmuir's Cretaceous fossils from the hill of Dudwick are 

 of flint, a substance not easily ground down by the denud- 

 ing agencies. 



I found several other curious fossils in Mr Longmuir's col- 

 lection. Greatly more interesting, however, than any of the 

 specimens which it contains, is the general fact, that it should 



