XXVlll PROCEEDINGS OP THE GEOLOGICAL SOCIETY. 



in the Sigillarice and Calamites ; of worms, the Gordius carbonarins, 

 Geinitz ; of mollusca, 5 species ; and of infusoria 4. Of the 14 species 

 thus enumerated, only 6 extend beyond the Saxon deposits. Of 

 plants, 156 species are named, of which 46 are common to the Saxon 

 and British Coal-formations. Many of these are again common to 

 the British and American coal, whilst others are not in the British, 

 though common to the Saxon and American deposits. With, there- 

 fore, sufficient elements for connecting the various local deposits into 

 one great whole, there are yet many and striking proofs of local 

 peculiarity. 



In respect to the five bands or zones of successive vegetable life : — 

 the 1st has only one species out of 23 common to it and the second 

 and third, so that the separation of the so-called culm-formation is 

 very marked ; between the 2nd and 3rd there are 33 species common, 

 or 32*35 per cent. ; between the 3rd and 4th, 28 or 23' 73 per cent. ; 

 between the 2nd and 5th, 33, or 20*12 per cent. ; between the 3rd 

 and 4th, 24, or 25'59 per cent. ; the 3rd and 5th, 33, or 23*57 per 

 cent. ; and the 4th and 5th, 35, or 22*43 : and it is remarkable that, 

 whilst the progression from the 2nd to the 5th is gradual and uni- 

 form, the relation between the 3rd and 5th, and 4th and 5th, are 

 nearly the same. Only three plants pass upwards into the Permian, 

 so that the coal-deposits are as abruptly separated from the Roth- 

 liegendes above, as from the culm-formation below ; an interesting 

 proof of the value of the evidence thus afforded by plants. 



The Zwickau coal consists of nine beds, amounting together to 

 about 80 feet, the greatest being 25 feet thick, and at a depth of 480 

 feet from the surface ; the total thickness of the deposits is 580 feet. 



Of the Permian strata Professor King has extended the limits from 

 the well-known locality at Cultra, on the bank of Belfast Lough, 

 to Ardtrea, in the county of Tyrone. The peculiarity of the small 

 limestone-deposit, thus abstracted from tlie overlying new red sand- 

 stone was not unnoticed by myself and by m.y then assistant, Mr. 

 Oldham, and I specially marked it out in my Report as requiring 

 further examination. At that time the fossils of the Permian sy- 

 stem were not so well known as at present, and, as I had then no 

 power of going beyond the district and seeking an illustration of 

 the true position of this rock elsewhere, I was obliged to content 

 myself by pointing out its uncertain character. The recognition 

 of the Permian character of the Ardtrea limestone is given in the 

 Journal of the Geological Society of Dublin ; and Professor King has 

 also published in the ''Annals of Natural History," two short papers, 

 in which he describes a new species of Productus, P. Schauroth- 

 ianus, found by himself in some Zechstein from Germany, and 

 passes in review the descriptions and determinations of others, most 

 of which had been recorded in his Monograph, discussing several 

 interesting questions regarding their structure. Of 45 species of 

 Palhobranchiata, noticed in his list, 22 are common to the German 

 and English formations ; 9 are common to the German and Russian, 

 and only 5 common to the German, Russian, and English ; numbers 

 which certainly suggest much matter for reflection, when it is remem- 

 bered that Russia may be regarded as the typical country of the 



