LIFE-ZONES IN THE BRITISH CAKBONIFEROUS ROCKS, 



191 



32. Limestone. 



AUoriama sulcata (common). 



Natieojjsia, 



34. Limestone. Produofus giganteus (in lower portion). 

 41. Fireclay cupper part gannister-like). Rootlets. 

 46. Nodular limestone. Natieopsix sp. 



48, Limestone (Hardraw Scar). Upper portion weathers red. 



Productii.1 gemireticulaius, var. Lithostrotion. 



cnstatiin. 



49. Black shale. 



Produchis gigantevs. 



51. Sandstone. Upper portion thickly bedded, lower portion flaggy. 



52. Black shale with nodules. 



Syncyclonema Somerhii. 



Fenestclla sp. 

 Athyris ambigua. 

 Chonetes BucMwna. 



„ painVionacea. 

 Bielasma Jinstata. 

 Orthis MicheUni. 



„ res>ij>inata. 

 Orthotetes crenistria. 

 Prodiictus aciileaUiis. 



,, costatus. 



„ giganteus ? 



„ iongisjnmts. 



„ soabrimdus. 



„ semireticulatus, 



„ vndatus. 



Mhynohonella pleurodon. 



63, Nodular Limestone. 3Iacroclieilina sp. 

 C4, Shales. 



Orthis Mu'heliiii, 

 Productvs seiniri'tlonlatm. 



65. Great Scar Limestone. Prodiictus giganteus. 



Rhynclumella trilateral 

 Spirifera, Uneata. 



Spiriferina cristata. 

 Ariculopecteii clatliratus, 

 Ctenodonta lavirostris. 

 Edmondia McCogi. 



, , u7iioniforiids (young). 

 Leiopteria squamosa. 

 Nucula luciniformis. 

 Psmdamiismm ellijjticum. 

 Scaldia Benediana. 

 iSyueyclonema Soicerbii. 

 Nacroclieilina acuta ? 

 Stroboceras snloatus. 

 PMllipsia sp. 



PogidonomyaBecJwri (abundant 

 in layer marked P. B., fig. 3). 



From the underset Limestone above Mill Gill, the following were 

 obtained : — 



Productus giganteus. 

 „ latissimus. 



„ punctatus. 



Prodvotus semireticttlatus4 

 Spirifor oralis. 

 Atliytis sp. 



Remarks : It will be observed that rroductns gigmitPAis ranges from 

 the bottom to the top of the .section and is met with both in the Lime- 

 stones and the shales. 



Posidonomya Becheri is very abundant in a layer of shale about 

 9 inches above the Great Scar Limestone, and may be useful in de- 

 scribing that limestone in other districts. 



The occurrence of Spirorbis lielicteres so low down on the carboniferous 

 system is especially noteworthj'. It is fairly abundant in the roof-shale 

 of (15) Coal, with which it is associated in the same way as with the 

 Coal-seams of the true Coal-measures. 



The two thin coals (1-5) and (40) may be used as indexes to the 

 Middle Limestone and the Hardraw Scar Limestone respectively, No. 15 



