252 



THE GEOLOGIST. 



tion, with the great breadth occupied in Ireland by calcareous 

 beds of the carboniferous era, where a similar deficiency 

 existed in the middle and superior members of the series. 

 This particular American series was deficient in tertiary rocks • 

 its cretaceous system was deficient in white chalk, the Neoco- 

 mean beds and the oolites were all absent, the lias and new 

 red sandstone were also deficient; and then came the coal, 

 succeeded by limestones, sandstones, and shales, and these 

 by altered strata and granite. The analogy between the 

 American cretaceous deposits and those of Europe was 

 very striking ; though specific differences did exist between 

 the fossils of the two countries, yet these differences were 

 very slight, merely marking the effect of local influence; 

 regarded as a group, the two deposits were identical, and 

 there could be no question of their contemporaneous deposi- 

 tion. Passing from the cretaceous deposits, we did not 

 meet with the series w4iich in Europe succeed to them, but 

 we passed suddenly to the coal formation, without a trace 

 of the fossils of the intervening beds ; whilst the plants of 

 the American coal measures, although they might differ 

 specifically from those of Europe, belonged to the same 

 leading groups — Stigmaria, Pecopteris, Neuropteris, Sigil- 

 laria, &c. In the limestones under the coal was shown 

 the state of the sea of that period. These were the 

 Productas, (of the P. antiquata group), and the Sypho- 

 nophyllia, resembling those of the English and Irish 

 carboniferous limestone, and the Pentremites sufficiently 

 characteristic to afford a good temporary designation for the 

 deposit. One fossil would seem to have strayed from 

 its proper place, the Calceola, but as no single shell could 

 be regarded as marking the boundary of a formation, this 

 was not an exception to the law ; the evidence given by a 

 large number of forms proved these beds to be the equiva- 

 lents of our carboniferous limestone. Beneath this lime- 



