[MATTHEW] GEOLOGICAL CYCLES IN MARITIME PROVINCES 133 



crust to strong ocean currents, while as yet the sea bottom is not far 

 from the surface, and still to some extent affected by wave action. 



A parallel condition now exists on the coast of New England and 

 Nova Scotia in the fishing banks that line it near the border of the 

 continental shelf. The late Professor A. S. Packard has called the 

 fauna characteristic of this tract of the sea bottom a Syrtensian fauna, 

 and such a phase of deposits may be called Syrtensian. 



Now, if we were to compare the Cambrian cycle of Acadia with 

 that of the Cambrian system, as limited by Director Walcott, and 

 accepted later by the European geologists, we find that the former is 

 much more comprehensive. This is shown by the faunas. Here are 

 some of the characteristic forms : 



Coldbrook — lAclirothyi-a (related to Acrotreta). 



Etcheminian — HolasapJms, Acrothyra. 



St. John Group. 



Div. 1 Band b. Protoleniis, {Olenellus horizon?) 



" c. Paradoxides, Conocoryphe. 

 Div. 2 " a. and h. Paradoxides cf. Forchammeri. 



" c. Olenus, horizon of, not known in Acadia. 

 Div. 3 Band a. Paraholina. 



" h. Peltura. 



" c. Dictyonema. 



" d. Tetragraptus. 



" e. Leptoholus. 



The Coldbrook rocks are mostly subœrial volcanics and an early 

 terrestrial phase of the Etcheminian, so that practically these form one 

 terrane. Shall we separate these from the Cambrian as belonging to 

 an older sysem? It now seems to me undesirable to do so (although 

 I have elsewhere advocated this), because they are parts of one geo- 

 logical cycle with the Cambrian, and the faunas are essentially Palneozoic, 

 though différent from the Cambrian faunas previously known. The 

 trilobite Holasaphvs resembles some early genera of the Ordovician, and 

 was referred to this system by the writer when first described. A study 

 of the stratigraphical relations of the beds in which it occurs, showed 

 clearly that it belonged to the base of the Cambrian succession, and 

 not to the top. So that although the Etcheminian fauna has features of 

 its own, these are not so decidedly different from the later Cambrian 

 types as to make it desirable to separate it from that system. 



At the top of the cycle another difficulty is encountered, for the 

 faunas here show that the two upper bands are Ordovician and not 

 Cambrian, in the sense that Cambrian is now defined. And so our 



