MODE XIII. CALCAREOUS INTRITE. 

 STRUCTURE III. TUBULAR. 



From the tower, or ancient pharos, at Dover 

 Castle. 



The same, from the banks of the Tees, and 

 other rivers in the north of England. 



The same, encrustrating various objects, as 

 birds' nests, plants, leaves, c. 



MODE XIII. CALCAREOUS INTRITE. 



This mode is rare, and of little consequence, 

 especially as the stones are not remarkable for 

 beauty, and seldom used in the arts. 



The most singular, is what Werner would call Porphyiitic. 

 a limestone porphyry ; being a compact lime- 

 stone of a reddish white colour, sprinkled with 

 minute crystals of white felspar. It was disco- 

 vered by Gillet Laumont, in the mountain called 

 Bonhomme, in the Alps. 



Another calcareous intrite is a fine grained Marble of 



Nonette. 



limestone, with angular spots of calcareous spar, 

 something resembling a porphyry. It is of a 

 yellowish white colour ; and bears the name of 

 marble of Nonette, from a place situate at the 

 confluence of the rivers Alagnon and Allier, in 

 the department of Puy-de-Dome. There is also 



