578 [March 12. 



stones of the Lune. The author then proceeds to describe some of 

 the lower groups of these rocks and their fossils. 



1 . The Coniston limestone. Most of the points of interest with 

 regard to this bed have been described by the author in a former 

 paper, of which an abstract has been given in the Proceedings of 

 the Geological Society.* 



It is of a dark blue colour, traversed occasionally by contem- 

 poraneous white calcareous veins, and its colour appears to be 

 derivable fi-om metallic oxides and not from carbon, as it burns to 

 a dark-coloured lime, which is used for agricultural purposes, and 

 as a cement stone. This limestone sometimes immediately overlies 

 felspar rock and porphyry, and the bottom beds, although generally 

 impure and siliceous and occasionally slaty, contain in some places 

 20 or 30 feet of beds fit for use. In Long Sleddale, however, a 

 singular trappean rock with great balls of agate underlies the lime- 

 stone, and in Kentmere the lower beds contain masses of coarse 

 conglomerate ; and although this is rare, yet as a general rule these 

 beds exhibit no marks of metamorphosis, and the green slates and 

 bedded porphyries below are so parallel to the limestone, that all 

 have evidently been disturbed together, while the passage from 

 the lower beds to the upper is almost instantaneous. 



The limestone bands are variable in their character, and not 

 strictly continuous, and the best beds are generally only a few feet 

 thick. On one side of Long Sleddale they are good, on the other 

 very degenerate, and occasionally they only form irregular rognons 

 in a dark fossiliferous slate. Above the limestones are shales and 

 soft slates, pyritous at the division of the beds f, and generally of 

 dark colour ; in these the rognons disappear gradually, but the 

 fossils ascend into them for some distance. At Sunny Brow the 

 slates are harder but too much jointed to be worked: at Ash Gill, 

 however, they are extensively quarried and contain many fossils, 

 one or two of them new species, but of Lower Silurian types. The 

 thickness of this group, wliich terminates the Lower Silurian series, 

 is probably upwards of 300 feet.| 



* Proceedings, &c., vol. i. p. 249. 



f In consequence of this appearance, unsuccessful attempts have been made 

 to obtain copper from these beds, but small veins and strings of sulphuret of cop- 

 per have been partially vk^orked to the east of Coniston. 



\ The author appends the following observations concerning the fossils of the 

 Coniston limestone. 



The Coniston limestone seems to contain all the characteristic fossils of the 

 IJansaintfraid section combined with many of the Bala species. The following 

 is the list of species : — 



Polyparia. 



Astrea, one or two species Stromatopora concentiica 



Favosites polymorpha Turbinolopsis bina 



F. spongites Retepora, scattered pores of a large 

 F. fibrosa species 



Porites pyriformis, in abnndance, and Catenipora escharoides 



a nearly allied species of larger size Tentaculites annulatus 



P. inordinata Tentaculites, a new species 



