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sions derived from the organic types of deposits remote from each 

 other, we seem in these transition fossils to have a secure starting 

 point ; and whether derived from the flanks of the Austrian Alps, the 

 eastern plains of Gallicia, the central regions of Russia, or the grey- 

 wacke chains of northern Germany or North America, they have at 

 least a family resemblance not easily mistaken. 



In the limestone of Cork Mr. Weaver observed impressions of the 

 vertebras of fishes associated with the fossils abounding in the grey- 

 wacke slate of the neighbouring country. The fact is in perfect ac- 

 cord with our present knowledge. Impressions of fish have long 

 been known of in some varieties of transition slate ; certain families of 

 Crustacea are eminently characteristic of formations of the same agej 

 remains of fish are commonly found in the mountain limestone of 

 Bristol ; shark's teeth occur in the mountain limestone of Northum- 

 berland ; and I need not perhaps remind you that impressions of fish 

 (sometimes accompanied with Crustacea) are found in incredible abun- 

 dance among the bituminous schists associated with the old red con- 

 glomerates of Caithness. Yet such is the inveteracy of our preju- 

 dices in favour of the hypothesis which admits nothing but what we 

 suppose the simplest forms of animal life into the older strata, that 

 even now we receive the facts opposed to it with doubt and hesitation. 

 What above all distinguishes the greywacke series of the South of 

 Ireland from the corresponding deposits in this country, is the occur- 

 rence of beds of pyritous shale abounding in impressions of Equiseta, 

 Calamites, &c, and containing beds of coal (whence many thou- 

 sand tons are annually extracted) interlaced with, and partaking of, 

 all the flexures of the transition system*. This fact, rendered doubly 

 striking by the horizontal and discordant position of the true carbo- 

 niferous limestone of the neighbouring districts, was an important 

 addition to our information, and was heard with no small surprise 

 by many members of this Society. It gives us, however, a new 

 term of comparison with the phsenomena of distant countries. The 

 greywacke chain of Magdeburg contains innumerable impressions of 

 true coal plants, and some of the carboniferous deposits on the con- 

 fines of Westphalia partake (like the deposits in the South of Ireland) 

 of all the contortions of the older transition series. 



On the descriptions of the old red sandstone and the carboniferous 

 limestone I shall make no comments ; but I think it right to recall your 

 attention to some valuable details respecting the metalliferous depo- 

 sits in the counties of Cork and Kerry. The copper ore of Ross 

 Island, on the lake of Killarney, does not constitute either metalli- 

 ferous beds or true veins, but is distributed in the form of branches 

 or strings, contemporaneous, like those of calcareous spar, with the 



* Small quantities of anthracite have been found here and there among 

 the old slate rocks of Cornwall ; and some portions of the oldest division of 

 the slate series of Cumberland are so carbonaceous as to have given rise to 

 borings and other works in search of coal. I have been informed that 

 similar unsuccessful attempts were formerly made in North Devon. But in 

 none of these instances, I believe, were true coal beds and plants, like 

 those described by Mr. Weaver) ever discovered. 



