Ch. XXTIL] 



CAMBRIAN ROCKS OF BOHEMIA. 



579 



may be considered as the most ancient fossils yet known in 

 Europe. 



We may reasonably anticipate that the Longmynd fauna, if ever 

 it shall become extensively known in the British Isles or elsewhere, 

 will be found to differ considerably from that of the Upper Cambrian 

 rocks, for the thickness of the beds unmixed with volcanic matter is 

 very great, and they must have required a great lapse of time for 

 their deposition. 



The most ancient fossils yet known in Europe (1864). 



Fig. 665. 



Fig. 664. 



OMTiamia racliata, Forbes. 

 Wicklow, Ireland. 



Oldhamia an-iiqua, Fortes. 

 WickloTV, Ireland. 



CAMBRIA X ROCKS OF BOHEMIA 



(Primordial Zone of Barrande.) 



I have already spoken (p. 574) of the splendid results of M. Bar- 

 rande's labors, published in 1846, in which year, after a prolonged 

 investigation of the geology of Bohemia, he discovered a great series 

 of palaeozoic formations, for which he adopted Sir R. Murchison's 

 general name of Silurian. The first or most ancient of his three 

 Silurian faunas, called by him primordial, corresponds with the Brit- 

 ish Upper Cambrian, as above described. The second tallies with 

 Murchison's Lower Silurian, and the third with the Upper Silurian of 

 the same author. When M. Barrande, a French naturalist, undertook 

 single-handed the survey of Bohemia, all the described species of 

 fossils previously obtained from that country scarcely exceeded 

 twenty in number, whereas he had already acquired in 1850 no less 

 than 1100 species; namely, 250 crustaceans (chiefly trilobites), 250 

 cephalopods, 160 gasteropods and pteropods, 130 acephalous mol- 

 lusks, 210 brachiopods, and 110 corals and other fossils. At a later 

 period, 1856, M. Barrande states that he had in his collection be- 



