300 PEOCEEDIN'GS OP THE GEOLOGICAL SOCLETT. [March 25, 



lying the graptolitiferous mudstones are also well seen, but the in- 

 tervening mndstones themselves are entirely hidden. 



On the moor, on both sides of Torve;; Beck, the cleaved Coniston 

 flags have been largely worked. They abound in Graptohtes, which 

 are well seen where the planes of bedding can be obtained ; but 

 cleavage renders this difficult, except in the weathered rubbish of 

 the quarries. Besides Graptolites priodon, which is found in great 

 abundance, a form possessing strong spines attached to the cell- 

 mouth is seen, which appears to be G. SedgwicTcii. 



On Torver Moor the Sheerbate beds, which succeed the cleaved 

 flags, are well seen, and have been worked. On the faces of these 

 G. priodon occurs, but not in such abundance as in the cleaved 

 beds. Associated with this is another species, apparently G. colonus, 

 Barr. Besides these Graptolites, the higher strata of the Coniston 

 flags yield other fossils*. The cleaved flags of Ireleth and Brough- 

 ton Moor also aff'ord Retiolites Geinitzianus f. 



The Coniston grits, the succeeding member of this series, in the 

 Lake-country are very barren in fossils. From these rocks, near 

 Sedbergh, Mr. Hughes has obtained from the lower tough grits, 

 principally from Helmside, near Dent, the following, viz. Cliona, 

 Spirorhis Lewisii, Ceratiocaris Murchisoni, C. rohustus, Graptolites 

 priodon, (7. sp., Pterinea tenuistriata, Ca^xliola interrvpta, Orthoceras 

 Ludense, 0. huUatum, 0. angidatum, and three other species ; and 

 from the higher sandy slates of the Coniston grits the following, 

 viz. Petraia, Encrinites, Ceratiocaris Murchisoni, C. rohustus, 

 Acidaspis n. s., Phacops, Graptolites, Pterinea tenuistriata, Cardiola 

 interrupta, Lituites, and Orthoceras three species J. Among the 

 fossils which occur in the lower tough grits at Helmside is a Grap- 

 tohte, G. Sagittarius, a form not recognized as an Upper-Silurian 

 species in any portion of the British Isles. 



The palseontological relations of the Coniston limestone to the 

 underlying green slates and porphyries have been already shown by 

 the occurrence in these latter of ashy strata with well-marked 

 Caradoc fossils §. The fossils which have been obtained from the 

 Coniston limestone place this member of the group in, or very near 

 to, the horizon of the Bala calcareous rocks. 



In or above the Coniston limestone there are no traces of the ash- 

 beds, or of the interbedded porphyries which are characteristic of the 

 rocks which underhe the lowest member of the Coniston group. In 

 the Bala country the same mode of occurrence seems also, to a great 

 extent, to hold good, as few igneous rocks are met with above the 

 horizon of the Bala limestone, the great igneous outbursts, so cha- 

 racteristic of the Caradoc rocks, having almost ceased before the 

 period of deposition of this limestone. In some districts of the 

 North of England the upper portion of the Coniston limestones are 



* Quart. Journ. Geol. Soc. 1866, vol. xxii. p. 483, 



+ This form is referred to Diplograpsus pristis in the Quart. Journ. Geol. 

 Soc. 1866, p. 483. More perfect specimens have convinced us that this is a 

 mistake. 



X Geol. Mag. vol. iv. p. 356. § Tom. cit. svpra, p. 482. 



