EOCKS OP BOHEMIA. 605 



underlying ijones are altogether absent from this, and instead of 

 them the following species occur : — 



Monograptus colonus, Barr, Monograptus Flemingii (?), 



bohemicus, Barr. testis, Barr. 



Eoemeri, Barr. 



Of these, the first is much the most abundant, and is found 

 wherever this division is met with. M. testis is very rare and 

 local. The other three I have only seen in the calcareous bands 

 and nodules towards the top of this zone. These calcareous bands 

 also contain other fossils found in the Upper Coldwell beds of Britain, 

 e. g. Halysites catenularius, Ceratiocaris, Cardiola interru^ta, many 

 species of Orthoceras, &c. 



E e 2 has a much richer fauna than Eel. I think this also 

 may be correlated with the Upper Coldwell beds of the English 

 lakes. It contains, besides the fossils mentioned as occurring at 

 the top of E 1, a great abundance of Bhynclionella navicida, which 

 occurs in thousands at Novy Mlyn in the Hlubocep valley. This 

 formation presents a very strong resemblance, both lithologically 

 and palseontologically, to the Wenlock Limestone. 



The beds of etages E and G are both correlated by Murchison 

 with the Ludlow rocks (Siluria, p. 380). I think that F 1, how- 

 ever, may be wholly or in part of Wenlock age. If e 2 is to be 

 referred to the Upper Coldwell beds of the Lake district, f 1 could 

 not be newer than the Coniston Grits, or lower part of the Bannis- 

 dale Slates, correlated by Mr. Aveline with the Wenlock rocks of 

 Wales. In any case, we cannot make any close lithological com- 

 parison of E and G with their British equivalents, for the lime- 

 stones vary much in thickness in the Bohemian basin itself, and must 

 be viewed as lenticular masses, rather than as deep-sea deposits ex- 

 tending laterally for a great distance. E f 2 has some fossils of a 

 decided Ludlow aspect, such as its large Pentameri and its fishes ; 

 whilst Goniatites, which are common in G, occur in this etage also. 

 Etage G presents undoubted affinity to the Ludlow rocks in its 

 fauna ; but that fauna is nevertheless a peculiar one, and each of the 

 three bands has its own species. 



Etage H has been referred by some geologists to the Devonian 

 series ; but M. Barrande has proved that it is Silurian. Its fauna 

 has a remarkable similarity to that of G g 2, and is one of the cases 

 so aptly described by M. Barrande as illustrating migrations, other 

 cases being those of d 1, d 3, and d 5, and of f 2 and g 3. Etage 

 H is probably to be correlated with the passage-beds of Britain ; 

 Professor Krejci figures a Lepidodendron from this horizon, and it 

 also contains abundance of another plant, Fucoides hostinensis. 

 Those who maintain the Silurian nature of some of the Old Eed 

 Sandstone rocks of the Welsh border would probably consider H to 

 be on the horizon of those beds. 



§ 5. Colonies. 

 Sir R. I. Murchison (Siluria, p. 380) remarks that " it now ap- 

 pears certain that his (M. Barrande's) Second Eauna, the 



representative of the Llandeilo and Caradoc of Britain, without any 



