Iviii PROCEEDINGS OP THE GEOLOGICAL SOCIETY. 



way are in tlie same category. Prance, Spain, and Sardinia, although 

 showing clear evidence of the existence of the first phase, are also 

 deficient of all trace of the last phase, only in Prance the forma- 

 tions which are classed as Lower Devonian contain numerous fossils 

 similar to the forms found in the different etages E, F, and G. 



In England, the Isle of Oesel, and the Harz, the characters of the 

 fauna of the etages G and H are partially represented; but in 

 England, amongst the six genera offish found in the Ludlow and Pas- 

 sage-beds, there are none of the cuirasses or armoured types. The 

 Trilobites are almost entirely wanting; the Dalmanites of the 

 groups D. Hausmanni and Bronteus are not represented. The same 

 is the case with the Nautilidae with the contracted mouth. Gonia- 

 tites are unknown, as well as Cardiola retrostriata. 



The United States of America form another category, showing 

 the principal characters which distinguish the fauna of the etages 

 G and H, viz., the sporadic appearance of the armoured fish, the 

 existence of the genus Calynwne amongst the Trilobites, a greater 

 development of the Dalmanites type, and the reappearance and re- 

 lative abundance of the Nautilidoe ; thus the most complete repre- 

 sentative hitherto known of the etages G and H is found in the 

 State of New York. 



The fifth chapter is devoted to the consideration of the connexion 

 between the etages P, G, and H of the Silurian basin of Bohemia 

 and the Devonian formations. After alluding to the evidence which 

 he has given that the lower calcareous Stage E contains by itself a 

 fauna almost as complete as that which is distributed in difierent 

 beds in other countries between the Lower Silurian and the Devo- 

 nian, the author proceeds to show that it would be a great error to 

 suppose that the upper etages P, G, H could belong, at least par- 

 tially, to the Devonian period. He shows, by carefully analyz- 

 ing the difi'erent classes of fossils contained in these three etages, 

 that, although they certainly do contain some species common 

 to the Devonian fauna, they are totally deficient in those forms 

 which have hitherto been considered as essentially characteristic of 

 the three subdivisions of the Devonian system, and that, on the other 

 hand, they contain many forms of a true Silurian character. 



The result of this examination shows that although the typical 

 forms of many Devonian species made their first appearance in the 

 Silurian formation, and although, as in the case of the Nautilidee, the 

 analogies brought forward would appear to show a greater connexion 

 between the Devonian faunas and the etage E than with the etage 

 G, no identical species, either of Trilobites, Nautilidae, or Goniatites, 

 occur in the two formations ; the same may be said of Pteropoda and 

 Gasteropoda. Of Brachiopoda there are 2 species common to etage 

 G and the Devonian beds. Cardiola retrostriata is a remarkable 

 instance of connexion between the Devonian phase and the youngest 

 Silurian phase, as well as between the older and younger phases of 

 the Upper Silurian ; and M. Barrande thus sums up the result of his 

 examination : — 



1. The last phase of the "faune troisieme" contained in the etages 



