SEDGWICK ON THE ROCKS OF N, WALES AND CUMBERLAND. 445 



2. Coniston flagstone. This group the author has formerly de- 

 scribed as Brathay flagstone, but now proposes to change its 

 name to Coniston flagstone for the sake of symmetry. No group 

 is better defined than this in the Lake country, and although 

 the Brathay and Coniston quarries are several hundred feet above 

 the preceding group, the series may be completed, in consequence 

 of the regularity of the dip, by connecting a succession of quar- 

 ries, and in this way the whole is estimated to be not less than 

 1500 feet thick. 



The mineral character of the Coniston flags resembles that of 

 the lower Denbigh flags, but is more altered by slaty cleavage *, 



Mollusca. 



Orthoceras, three smooth species, like Orthis vespertilio 



those from the lower Bala lime- O. virgata 



stone O. actoniae 



Lituites cornu-arietis Orthis n. sp. (named in MS. crucialis), 

 Euomphalus ? perhaps two species under the same 



Turritella, or Terebra name 



Turbo ? O. radians 



Leptoena depressa Orthis n. sp. ? with fine simple ribs 



L. n. sp., decussated Orthis n. sp., same as from Dudley, a 

 L. sericea curious rough species 



L. transversal is and another Atrypa (Spirifer), resembling S. acumi- 

 L. (Orthis) grandis, Sil. Syst. nata 



Orthis canalis A. (Spirifer), a smooth species, ? new 



O. alternata ? Atrypa affinis 



O. testudinaria Spirifer n. sp. named in MS. 



O. flabellulum )3 S. n. sp. ? small variety of S. radiatus 



Crustacea. 



Cytherina laevigata A. tyrannus 



Paradoxides quadrimucronatus Illoenus (Bowmanni, MS.; called Bu- 



Calymene Blumenbachii mastus Barriensis in a former list) 



Calymene n. sp. Brontes, undescribed species (vide Port- 



Asaphus Powisi lock's report). 



The corals, both as to species and numbers, are precisely similar to those 

 north of the Berwyns. 



In the abundance of Leptcena depressa, L. transversalis, Orthis radians, and 

 above all, O. inflata, with spiral shells, and Lituites cornu-arietis, there is an 

 analogy with the beds north of the Berwyns : but the presence of Orthis Actonice 

 and O. virgata, with Spirifer (crucialis), which are also plentiful, approximates the 

 group to that from Bala and the Coniston limestone; it resembles also these latter 

 beds in possessing the smooth Orthoceratites, Encrinites, and Illcenus (Bowmanni), 

 but it differs in the scarcity of Orthis canalis, O. testudinaria, and 0. vespertilio, 

 and the absence of 0. flabellulum, O. alternata, Spirifer radiatus, Agnostus pisi- 

 formis, Trinucleus Caractaci, and Asaphus tyrannus (one doubtful specimen of 

 this latter having been found), fossils characteristic of the lower group in Wales. 



An undescribed Paradoxides, a tail of a new Brontes, a curious undulated 

 fossil (perhaps crustacean), a new Tentacidites, and abundance of Cytherina 

 (a marine Cypris) seem peculiar to the Coniston limestone; and the last is a 

 very interesting fossil, not having been known before in rocks of the Silurian 

 series. 



* The author observes, with reference to this condition, that he has observed 

 in the flags in question distinct cases of a second cleavage plane entirely distinct 

 both from joints and bedding. 



VOL. I. H H 



