312 Viscount d'ARCHiAC and M. de Verneuil 



Carboniferous system, in which the calcareous rocks are nevertheless very exten- 

 sive, rather more than a sixth less are found than in the two preceding, and four 

 only are common to the Devonian system. Lastly, there are three species only 

 found in all the three periods. 



IV. Foraminifera. — The Foraminif era of the Palaeozoic formations have as yet been 

 very little studied, and we are well acquainted only with those which have been 

 pointed out by M. Fischer in the carboniferous limestone of the government of 

 Wladimir and the heights of Samara on the Volga, in which escarpments more 

 than two hundred feet thick are entirely composed of them *. Mr. Phillips men- 

 tions remains of this class in the Devonian limestone of Cannington Park in North 

 Devon, but without detailing their characters or the number of genera and species. 

 It is moreover very probable that further researches will make us acquainted with 

 a greater number of Palaeozoic Foraminifera, analogous to those found in the se- 

 condary, tertiary and modern formations, wherever circumstances may have been 

 favourable to their preservation. 



V. Radiata. — The remains of animals of this class almost all belong to the great 

 family of Crinoidea. The Asterias are very rare, and of Echinodermata four Cida- 

 rites alone are quoted in the Carboniferous system, in Ireland f, Scotland J, En- 

 gland §, Belgium || and Russia ^, and some fragments have been pointed out in the 

 Devonian system. Our attention will not be particularly arrested by many genera 

 of Crinoidea, which contain only two or three species, and of which the greater part 

 have not been noticed except in a single locality, whether Silurian, Devonian, or 

 Carboniferous ; but we will pass on to the most important genera. 



The Cupressocrinites, scarcely more than one excepted, are Devonian, from the 

 Eifel and the right bank of the Rhine. The Pentremites, of which fourteen species are 

 known, are, on the other hand, almost all Carboniferous. It is nevertheless worthy 

 of remark, that six species are stated by Dr. Troost to be associated with Calceola, 

 Calymene, Terebratula Wilsoni, &c., in Ohio and Tennessee, in beds probably older 

 than the mountain limestone**. In Europe a single species is mentioned at 

 Brushford, in North Devon, in the Devonian bedsff ; and it ascends into the carbo- 

 niferous limestone (Ratingen), in which formation the genus attained its fullest 

 development. The Poteriocrinites are all from the Carboniferous series, and are 



* In their last expedition in Russia, Mr. Murchison and M. de Verneuil ascertained that these Fora- 

 minifera (Fusulines of Fischer, Oryct. Govern, de Moscou ; Alveolines of d'Orbigny) characterise the 

 upper beds of the mountain limestone, and range over very distant and extensive districts. 



t Dr. Buckland's Bridgewater Treatise, vol. i. p. 416. % Ure's Rutherglen, pi. 16. 



§ Phillips, Geol. Yorks., part 2, p. 208. 



II De Koninck, Recherches Anim. Foss. Belgique. f Eichwald, Jarhb. fiir Miner. 1840, p. 627- 



** Trans. Geol. Soc. Pennsylvania, vol. i. part 2, p. 224. 



\\ Phillips's Palaeozoic Fossils, p. 29. 



