604 J. E. MAER ON THE PEEDEVONIAN 



Monograptus cyplius, Lapw. 



Becki, Barr. 



tenuis, Portl. 



proteus, Barr. 



spinigerus, Nich. 



triangulatus, HarJcn. 



turriculatus, Barr. 



Eastrites peregrinus, Barr. 



Linnasi, Barr. 



Diplograptus folium, His. 



tamariscus, Nich. 



Climacograptus scalaris, His. 

 Eetiolites, sp. 



All the above species are characteristic of the Birkhill Shales. No 

 other fossils than Graptolites have yet been found in strata proved to 

 belong to this zone. 



And not only does this zone resemble the Birkhill Shales, but it 

 can, like them, be divided into a series of subzones characterized by 

 various species of Graptolites. In the limited time at my disposal I 

 was unable to define these subzones, especially as the whole of this 

 zone is never exposed in one continuous section ; but I made out 

 that the lowest subzone consisted of what I may describe as " wafer 

 shales" — black shales so thin as to be broken into any shape 

 desired by the fingers, and crowded with Graptolites chiefly of 

 two species, viz. Rastrites peregrinus and Climacograptus scalaris^ 

 which occur in thousands at this horizon, to the exclusion of any 

 great abundance of other species. This subzone is well seen in the 

 valley running up the side of Mount Kosov, near^Kraluv Dvur 

 (Beroun), also in the Chodaun valley, between Zelkovice and 

 Libomysl, and in many other places. Another subzone is character- 

 ized by the abundance of Monograptus turriculatus ; and this, as in 

 Britain, occurs high up in the series. It is seen between Kuchelbad 

 and Gross Kuchel, at Litohlav Mill, and near Zelkovice. 



The next overlying fauna occurs in much more flaggy shales, 

 with calcareous bands and concretions in places. Its graptolitic 

 fauna is that of the Brathay Flags of the Lake district, and a 

 similarity is observable in the lithological character of the two 

 deposits. This is specially marked at Branik, where the beds are 

 not so black as is usual in this zone in Bohemia. I have seen 

 the following Graptolites in this zone (all of which occur at 

 Yyskocilka, where the underlying zone is absent) : — 



Monograptus priodon, Bronn. I Cyrtograptus Murchisoni, Carr. 

 vomerinus, Nich. \ Retiolites Geinitzianus, Barr. 



KM of these, except the Cyrtograptus^ are abundant in many localities. 

 The negative evidence is as strong as the positive, for although the 

 two described faunas are not separated by any beds such as the 

 Tarannon Shales (Pale Shales) of Britain, they do not, so far as I have 

 seen, possess a single species in common. 



A band of limestone always occurs between this zone and the 

 overlying one. It contains abundance of Cardiola interrupta^ 

 Orthoceras, &c., and is probably about the horizon of the Middle 

 Coldwell beds of the Lake District. 



The overlying graptolitic fauna occurs in sandy shales, very 

 similar to those of the Upper Coldwell beds of the English Lake 

 district. The Graptolites already enumerated as occurring in the 



