348 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 23, 
closed in the Wealden, and that its fossils have an Upper Neocomian 
character, with a clear affinity to a Spanish series. He regarded 
the Wealden of North Germany as not strictly contemporaneous 
with that of England, and stated that the “ Hilsconglomerat ” in 
Brunswick was a shore-deposit, but that its relation to the Wealden 
could not be observed. 
2. On Dexe-minine with Revation to the Paystcat Srructure and 
Minrrat-Bearine Srrata of the Sourn-wexsr of Irenanp. By 
Samvurt Hypr, Esq. 
(Communicated by R. Etheridge, Esq., F.G.S.) 
[ Abstract. | 
Tue author described the general structure of the country in the 
south-west extremity of Ireland, which he stated to consist of a 
series of rocks analogous to the “ Killas” of Cornwall, and belong- 
ing to the upper part of the Lower, or the lower part of the Upper 
Devonian series. He combated the opinion which had been ex- 
pressed by the late Professor Jukes, that copper-ores would not be 
found in the district in sufficient quantities to make mining there a 
remunerative process. In support of his thesis, he cited the Bear- 
haven mines, established about fifty years ago, the Allitries and 
Ballycummisk mines, and the Coosheen mine. He stated that in the 
Ballyecummisk mines a depth of 200 fathoms has been reached, and 
that some of the shafts at Bearhaven are much deeper. These deep 
workings were said to yield large returns of ore. In opposition to 
the opinions stated by the late Professor Jukes, the author main- 
tained that the copper lodes were of the same nature as those of 
Cornwall, and he described them as running in a similar direction, 
namely, 10°-25°N. of E. From the similarity in the geological 
constitution of the country, and in the direction of its mineral veins, 
the author was inclined to infer a former continuity between the 
south-western promontories of the islands of Great Britain and 
Treland. 
Discussion. 
Mr. Davin Forzss protested against the notion that the Devonian 
strata themselves were metalliferous, the veins being of much later 
date—in the present case Postcarboniferous. He maintained that 
there was no valid reason for supposing that the veins became unpro- 
ductive with increased depth, and opposed the notion that they had 
been filled in by segregation from the surrounding rock. He alluded 
to the use of spectroscopic analysis in such inquiries, and remarked 
that as no trace of copper is to be found in the rock even immedi- 
ately adjacent to veins, we should have to admit, on the hypothesis 
of segregation, that the rock must originally have contained pre- 
cisely the amount of metal segregated in the veins. 
Mr. Erneriner agreed with Mr. Forbes as to the date of the fill- 
ing in of the veins. He also maintained the justice of correlating 
the rocks with those of the Cornish area. 
Mr. Hyor briefly replied. 
