Rev. A. Irving — On the “ Permian ” and “ New Red.” 309 
abont 50 or 60 feet below the bottom of the Orten Scar Limestone 
at Ashfield, Ravenstonedale, Westmorland. Associated with the 
tooth, Prof. Nicholson informs me, were a large nurnber of Corals, 
Brachiopods, and other fossils. Of the Corals the most characteristic 
and abundant were Lithostrotion Martini, L. irreguläre , Syringopora 
geniculata, and Zaphrentis Bowerbanki. 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. Benriie, J. Linn, and J. Simpson, and the 
Rev. T. Brown, M.A. 
EXPLANATION OF PLATE XIII. 
Fig. 1 . — Dentalium inornatum, M‘Coy ? twice nat. size. L. Carboniferous, Ardross, 
Fife. Coli. Geol. Survey, Scotland. 
,, 2. — Fissodus? Pattnni, E. Eth., jun. ; three times nat. size. Calderwood 
Series, East Kilbride. Cabinet of Mr. A. Patton. • Anterior view ? 
„ 3. — The same \ another speciraen, posterior view ? three times nat. size. Koof 
of the Splint Coal, Edge Coal Series, Lean Pit, Einneil, near B’oness, 
Linlithgowshire. Coli. Geol. Survey of Scotland. 
„ 4 . — Oracanthm Milleri, Ag. lateral view, nat. size. Calderwood Series, 
East Kilbride. Cabinet of Mr. A. Patton. 4 a, tubercules enlarged. 
„ 5. — The same ; posterior view ? nat. size. 
„ 6. — „ anterior „ „ 
„ 7 . — Psammodus rugosus, Ag. var. ; view of crown of the tooth, nat. size. 
Carboniferous Limestone, Eavenstonedale, 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 magnilied to show the 
characteristic fringed ridges.” 
Y. — On THE SO-CALLED “ PERMIAN ” AND THE New ReD SANDSTONE 
Formations. 
By the Eev. A. Irving, B.A., B.Sc., F.G.S., 
of Wellington College, Wokingham. 
O N the 6th March, 1874, 1 communicated a paper on the “ Geology 
of the Neighbourhood of Nottingham ” 1 to the Geologists’ 
Association, which was subsequently printed in extenso in their Pro- 
ceedings. üp to that time I believe the definition laid down by the 
Government Survey, and imported intotext-books, of the distinction 
between the so-called Permian and the New Red Saudstone 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 
conrse, 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, 1 perused carefully the memoirs of 
1 See Geol. Mag. 1874, New Series, Yol. I. p. 314. 
