Notices and Extracts from the Minutes of the Geological Society. 173 



are firmly ag-glutinated together by a base^ in which may be observed a few 

 minute specks of calcareous spar. The g-ranular appearance is very distant and 

 in small stripes ; the cement is nearly wanting-^ which circumstance serves to 

 connect it with No. 2, of which two rocks I understand the greater mass of the 

 islands to be composed. 



No. 4. In this the interstices are almost entirely filled by the cement, so that 

 the granular structure is only to be observed in patches. This rock approaches 

 to the saccharine aspect, and shows many specks of calcareous spar. 



No. 5. In this the granular structure of the stone is almost lost ; the aspect 

 is truly saccharine^ and the surface glistens with calcareous spar. 



The five specimens above enumerated afford a perfect gradation from a 

 rough and obviously fragmented rock to a limestone almost compact ; and 

 may thus be useful in pointing out the origin of some calcareous beds, in which 

 a similarity of structure exists, but where the mode of formation cannot be 

 traced to operations so recent and so obvious as in the Bermudas. The large 

 grained rock being found along the coast, and the finer grained inland, affords 

 a beautiful confirmation of the assumed origin of the islands ; since the accu- 

 mulation of such materials by surge and winds, would evidently effect that dis- 

 position : and as I understand the hills no where exceed 200 feet in height, 

 and are no where so much as five furlongs from the sea, the agents seem quite 

 adequate to this effect. 



In enumerating the specimens, I have neglected No. 6, — a yellowish-red 

 coloured limestone of great compactness, in which, though evidently com- 

 posed of small grains united by cement, the grains are not readily distin- 

 guishable, except in patches, or by pohshing. This last specimen would carry 

 the gradation a step higher, but 1 have reason to believe that the stone is of 

 rare occurrence : I am inclined to think that it occurs in patches, and owes its 

 origin in a great measure to the same causes that produce the stalactites of 

 Bermuda. 



12, Notice on some Fossil Shells from Langton- Green, near Tunbridge Wells. 

 By Sir Alexander Crichton, m.g.s. &c. [Read April 19, 1822.] 



These shells are found in a sandstone quarry, worked in the ferruginous 

 sand at Langton-Green, about two miles from Tunbridge Wells, on the 

 Groombridge road. No shells are observed in the substance of the sandstone 

 itself; but they abound in the oval-shaped nodules of ironstone, consisting of 

 oxide of iron, sand, and clay, which the sandstone contains. These nodules 

 are from one and a half to two feet in their longest diameter, and from ten 



