EARLY DEVONIC HISTORY OF NEW YORK AND EASTERN NORTH AMERICA 9 



5 Trap, vesicular, hard and black, weathering red. 



6 Calcareous shale and limestone, with honestone. Many layers are 

 fissile and shaly, weathering buff, others are hard and silicious. The lime- 

 stones contain Favosites gothlandica, Strophomena rhom- 

 boid a 1 i s, etc. In the upper part of this series there appears to be a 

 conglomerate 14 feet thick, capped by honestone 36 feet thick. 



7 Massive trap. 



8 Limestone highly fossiliferous. Among its fossils are Favosites 

 gothlandica, F . polymorph a, F . b a s a 1 1 i c a, Strophomena 

 rhomboidalis, S . punctulifera, Calymene b 1 u m enbachii, 

 A t r y p a reticularis. 



9 Trap, highly ferruginous. 1 



It is instructive to observe the large amount of bedded trap or volcanic 

 ash in the above section. This accords with the presence of large quantities 

 of apparently interstratified igneous rock in the Kingston group and in the 

 Cobequid mountains, as already noticed. Such interstratified volcanic mat- 

 ters are abundant in some parts of the Silurian of Great Britain. They are 

 comparatively rare in other parts of Nova Scotia, though beds of this kind 

 occur in New Canaan. Similar traps occur in Gaspe, but they are absent 

 from the typical Upper Silurian of New York and western Canada. Their 

 presence indicates the recurrence of volcanic eruptions at frequent intervals 

 during the Upper Silurian period. 



A collection of fossils from the beds at Dalhousie and its vicinity has 

 been kindly communicated to me by Professor Bailey, and has been submit- 

 ted to Mr Billings, who regards the species as equivalent to those of the 

 Port Daniel limestones of the northern side of the Bay de Chaleur, which 

 may be regarded as intermediate in age between the Niagara and Lower 

 Helderberg groups, and therefore probably not far from the horizon of the 

 Upper Arisaig series, or perhaps between this and the Lower Arisaig group. 



The following fossils from Dalhousie and Restigouche, now in the 

 Museum of the University of New Brunswick, have been determined by 

 Mr Billings. The assemblage is in the main that of the Lower Helderberg. 



Favosites basaltica Spirifera cycloptera 



Favosites gothlandica Atrypa reticularis 



Zaphrentis 11. s., same as one in the Gaspe Cyrtia dalmani 



limestone Rhynchonella vellicata Hall 



Stenopora Athyris princeps, or allied 



Halysites catenulatus Leptocoelia, allied to L. hemispherica 



Syringopora Fenestella 



Diphyphyllum Megambonia, allied to M. ovoides Hall 



Orthis tubulistriata Hall, or allied Conocardium 



Orthis oblata Hall Pleurotomaria, allied to P. labrosa Hall 



Strophomena rhomboidalis Euomphalus sinuatus (?) 



Strophomena punctifera Contad Dalmanites 

 Strophomena varistriata 



1 The total thickness of the above series is not stated by Professor Hind. 



