•]6 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 1 894, 



south by the Ashprington volcanic series, and on the east by the 

 Lower Devonian of Beacon Hill and Windmill Hill (Cockington Grits). 

 The shaly ' Calceolen-kalk,' or Eifelian Limestone, which gradually 

 comes on in the upper part of the series is frequently brought up in 

 the limestone masses of Torquay and elsewhere by contortion. 

 Fossils common in the Eifelian slates are Atrypa reticularis, Strepto- 

 rhynchus crenistria, and Spirifer speciosus. Both by fossil and 

 stratigraphical evidence the position of certain limestone patches in 

 connexion with the Ashprington volcanic series is proved to coincide 

 with the Eifelian Limestone, and we are thus supplied with a reliable 

 date for the commencement of this phase of volcanic activity, viz., 

 the later stages of the Eifelian deposition. This is also borne out 

 by the absence of volcanic materials in the Lower Devonian and 

 Eifelian Slate areas. How long it continued is not equally clear, 

 but there seems, he says, to be evidence of vulcanicity in other 

 areas in connexion with a great development of Middle Devonian 

 Limestone. 



Continuing the Middle Devonian sequence, we have now to con- 

 sider the main mass of Devonian Limestone. Mr. Ussher says there 

 is absolutely no line of demarcation between the upper horizon of 

 the ' Calceolen-kalk ' and the bedded limestones above, which are 

 held to be on the String 'ocephalus-horizon • hence their separate 

 treatment is purely arbitrary. It would take up too much time 

 to follow the interesting evidence, chiefly palaeontological, adduced 

 by the Author in connexion with the Torquay, Dartington, and 

 Newton Abbot districts. In his summary he infers, generally, 

 that the bedded limestones which succeeded the shelly and coralline 

 bands, representing the Eifelian Limestone, became in places the 

 bases for more uninterrupted coralline growth. This growth, he 

 considers, was locally continuous to the earlier stages of the Upper 

 Devonian period. In the meantime, proofs are not wanting that 

 the accumulation of Middle Devonian Limestone took place contem- 

 poraneously with the Ashprington volcanic outbursts ; so that, in the 

 words of Mr. Champernowne with reference to the stratigraphical 

 difficulties presented by that series : — " All these anomalous ap- 

 pearances are at the same time quite capable of being accounted 

 for, if we consider what might take place in a reef district which 

 was at the same time the arena of volcanic disturbance." That 

 gentleman's experience, moreover, fully endorsed De la Beche's 

 view that certain of the limestones are laterally replaced by 



