52 MATTHEW. 



both at the top of the basal conglomerate. It is plain there- 

 fore, that the Etcheminian terrane was entirely eroded at Man- 

 uel's Brook before the first member of the Cambrian was laid 

 down, though perhaps the harder calcareous masses remained to 

 contribute to the boulders in the conglomerate. This is parallel 

 to the conditions in New Brunswick on the Kennebecasis River, 

 except that there are no limestones or remains of them in that. 

 valley, and the Etcheminian is entirely wanting. 



4. The Etcheminian Fauna distinct from the Cambrian. 



If there is a break in the geological succession, such as we 

 have shown by the above sections, there should be some differ- 

 ences to mark it between the faunas of the two terranes. This 

 we find to be the case, and believe the difference to be an im- 

 portant one. 



In the Etcheminian beds the author has found no trilobites,, 

 though other classes of animals, such as Gasteropods, Brachio- 

 pods and Lamellibranchs, occur, with which trilobites else- 

 where are usually associated in the Cambrian and later geo- 

 logical systems ; and the absence (or rarity ?) of the latter 

 appears to have special significance, since they are the most 

 notable fossils of the Cambrian deposits, and serve better than 

 any other organisms to differentiate the several zones of that 

 important system. 



The fossils which are most abundant and most characteristic 

 of the Etcheminian of Trinity Bay, Newfoundland, are shells of 

 the genera Hyolithcs and Orthotlicca, not distinguishable in size 

 or general appearance from the usual forms of the Cambrian. 

 Conical shells resembling PaUvacinceci" are rather common, and 

 others belonging to the genus Scoiclla. The shells of Gastero- 

 poda outside of those named above, as well as the Brachiopoda 

 and Lamellibranchiata, are small, almost minute. We have thus 

 far found no Linguloid brachiopod, nor any Acrothele in this ter- 

 rane, though they are common in the Protolenlan zone of the 

 Cambrian in New Brunswick. 



1 Such shells are usually refen-ed to Stenotheca, but, as the author has shown in. 

 previous publications, this name is not applicable. 



