Species of 

 this assise. 



72 



roundness of many of the grains of calcium phosphate would lead one to 

 suspect the presence of Foramenifera, but I was unable to observe the 

 smooth pitted surface by which the Foramenifera of the Protolemus beds 

 may be recognized. 



Hyolithes, small, ^tubes 3 



Acrothyra signata-prima ventral 18, dorsal 16 



Acrotreta papillata-prima " 1 " 



Leptobolus torrentis " 1 " 



Lingulepis pumila " 3 " 4 



Lingulella cf. longovalis " 1 " 1 



Obolus torrentis " 1 " 1 



Indiana ovalis-prima ........ carapace 1 right v. 1 



Escasona 1 ? ingens 'I left v. 1 



Notwithstanding that all these genera are Etcheminian, and that we 

 can no longer separate the Coldbrook volcanic rocks as pre-Cambrian, 

 there appears to have been an advance or growth in the species as they 

 pass upward to the next terrane. This will appear as regards their 

 size if they be compared with the most nearly related Etcheminian forms. 



Their 



comparative 



minuteness 



Acrothyra signata prima . . .2x2^ A. signata 2x3 

 Acrotreta papillata-prima. . 2x2 A papillata 2^x2^-3 



Leptobolus torrentis 3x2 L. atavus 5x3 



Lingulepis pumila 6x4 L. longinervis 11x8 



Lingulella cf. longovalis .... 7x5 L. longovalis 9x6 



Obolus torrentis 6x6 O. triparilis 9x8 



Indiana ovalis-prima 5Jx3| I. ovalis 4Jx3|- 



Escasona ? ? ingens 6x6^- ? 



The fossils of the first column are of the Coldbrook terrane, those of 

 the second, Etcheminian. 



Throughout the inarticulate Brachiopoda represented here, there 

 appears to have been an average increase of nearly fifty per cent, both in 

 the length and breadth of the valves in the resembling forms of the 

 Etcheminian (Lower) fauna. There seems not to have been a dwarfing 

 of the species of this assise from incongenial habitat, as its fine shales 

 should rather have shown larger species. In the Etcheminian terrane the 

 advent of shaly beds was accompanied by the appearance of large species, 

 as for example the two typically largest species of the two Etcheminian 

 faunas, Lingulepis Gregwa (Assise E. 1 d.) of the Lower fauna and 

 Obolus Bretonensis (Assise E. 3d.) of the Upper. 



