346 C. LAPWOETH ON THE MOFFAT SERIES. 



that there is more than one main band of black shales. The proofs 

 brought forward in the present paper that all the bands of black 

 shale m the Moffat district rise along anticlinal lines render that 

 hypothesis untenable, and rid us at once of the necessity for any 

 unconformity whatever. 



As for the calcareous beds of Girvan&c, which contain, in imme- 

 diate juxtaposition and apparent intermixture, Brachiopoda &c. 

 elsewhere peculiar to beds of Llandovery, Bala, and Llandeilo age, 

 it was almost certain that towards the N.W. of the southern up- 

 lands (as in Sweden, &c.) the black beds are in great part replaced 

 by calcareous rocks, and that we have there a parallel instance of 

 what takes place in the Moffat district, the three distinct Grapto- 

 litic faunas of Moffat (whose accidentally intermingled fossils may 

 often be there collected from the talus of a single cliff) being paral- 

 leled by the three testaceous faunas of Girvan &c. When it is 

 recollected that in certain localities these shell-bearing rocks are 

 highly conglomeratic, in others involved, shattered, and more or less 

 metamorphosed, it is probable that in some spots many of the forms 

 are derivative, and in others that they owe their apparent intermix- 

 ture to a variety of accidents. 



In answer to Mr. Hicks and Prof. Hughes, the author said that 

 the chief palaeontological break in the south of Scotland occurred at 

 the base of the Birkhill shales, i.e. between the Bala and Lower 

 Llandovery beds. There is no physical break at this horizon, and 

 the^ zoological break is apparent only where the Moffat beds are 

 typically developed. Where the Birkhill beds lose their black-shale 

 bands as they pass to the northward, it is impossible to draw a line 

 of demarcation between the Llandoveries, both Upper and Lower 

 Llandovery being probably represented by the greywackes of Peebles 

 and Lanarkshire. 



