﻿Rev, A. Irving — On the " Permian " and " New Bed." 309 



about 50 or 60 feet below the bottom of the Orton Scar Limestone 

 at Ashfield, Ravenstonedale, Westmorland. Associated with the 

 tooth. Prof. Nicholson informs me, were a large number of Corals, 

 Brachiopods, and other fossils. Of the Corals the most characteristic 

 and abundant were Lithostrotion Martini, L. irregidare, Syringopora 

 geniculata, and Zaphrentis Boioerbanld. Cabinet of Prof. Nicholson. 



I am much indebted for information and the loan of specimens to 

 Professors Williamson and Nicholson, and Messrs. E. W. Binney, 

 F.R.S., A. Patton, J. Bennie, J. Linn, and J. Simpson, and the 

 Eev. T. Brown, M.A. 



EXPLANATION OF PLATE XIIL 



Fig. L — Dentalium inornatuin, M^Coy ? twice nat. size. L. Carboniferous, Ardross, 



Fife. Coll. Geol. Survey, Scotland. 

 ,, 2. — F/ssodus? Fattoni, B,. Eth., jun.. ; three times nat. size. Calderwood 



Series, East Kilbride. Cabinet of Mr. A. Patton. Anterior view ? 

 ,, 3. — The same ; another specimen, posterior view ? three times nat. size. Eoof 



of the Splint Coal, Edge Coal Series, Lean l^it, Kinueil, near B'ouess, 



Linlithgowshire. Coll. Geol. Survey of Scotland. 

 „ 4. — Oracanthus Milleri, Ag. lateral view, nat. size. Calderwood Series, 



East Kilbride. Cabinet of Mr. A. Patton. 4«, tubercules enlarged. 

 „ 5. — The same ; posterior view ? uat. size. 

 „ 6. — ,., anterior „ „ 



„ 7. — Fsammodus rugosus, Ag. var. ; view of crown of the tooth, nat. size. 



Carboniferous Limestone, Iiavenstonedal&, Westmorland. Cabinet of 



Prof. Nicholson. 

 „ 8. — The same. Side view showing the lateral prolongation ; nat. size. 

 ' „ 9. — Portion of surface of the crown of the same tooth magnified to show the 



characteristic " fringed ridsres." 



V. — On the so-oallbd "Permian" and the New Red Sandstone 



FOEMATIONS. 



By the Eev. A. Irving, 33.A., B.Sc, F.G.S., 



of Wellington College, Wokingham. 



^N the 6th March, 1874, 1 communicated a paper on the " Geology 

 of the Neighbourhood of Nottingham"^ to the Geologists' 

 Association, which was subsequently printed in extenso in their Pro- 

 ceedings. Up to that time I believe the definition laid down by the 

 Government Survej^ and imported into text-books, of the distinction 

 between the so-called Permian and the New Eed Sandstone forma- 

 tions had not been called in question very prominently. Like other 

 students of geology, I myself accepted in good faith the dictum as to 

 a great break existing between the two formations, indicating, of 

 course, an enormous period of time. I could not, however, help, as 

 I walked along the banks of the Leen, — which flows along the foot 

 of the western escarpment of the Lower Bunter Sandstone, — trying 

 to realize what this really meant; and the thought was not without 

 its influence in stimulating me to try and work out such evidence as 

 the district might afford, of the reality of this great hypothetical 

 interlude in the geological succession of strata. Wishing to make 

 myself acquainted with all the observations which had been pre- 

 viously made upon the subject, I perused carefully the memoirs of 



1 See Geol. Mag. 1874, New Series, Vol. I. p. 314._ 



