81 



Division N. of the Newfoundland rocks seems to be a distinct formation 

 although intimately connected with the Upper Calciferous. We here first 

 meet with the European genera Aerotreta, N'ileus, Solometopus, and Am- 

 pyx. We have 48 species of fossils from this deposit of which 12 are 

 found in the lower rocks and 3 pass upwards. I think it should be added 

 to the Upper Calciferous. 



Next comes the L^vis formation with about 220 species of fossils of 

 which 51 are graptolites, manj of them like those of the Skiddaw slates. 

 A few, apparently 4 or 5 species, are Calciferous and about the same 

 number Chazy. On the whole, this is a distinct fauna. There is a great 

 break between it and the Calciferous below, and another between it and 

 the Chazy above. Many of the trilobites are closely allied to the charac- 

 teristic species of the upper Lingula Flags and Tremadoc slates. 



Above the L^vis, we have the Sillery formation with only three species of 

 fossils, — Oholellapretiosa and two small Lingulce, the latter undetermined. 



Now in comparing all these formations with the lower part of the Eng- 

 lish Silurians, I believe, we have one horizon, the Lower Lingula Flao-s 

 and St. John's Group, certainly identified, and another, the Ldvis, and 

 Skiddaw paralleled by some but not perfectly conclusive evidence. I do 

 not see very clearly how to correlate the intermediate formations. We 

 seem to have more than there is in the English series. Adding Div. n of 

 the Newfoundland rocks to the Upper Calciferous the columns up to the 

 Chazy would stand thus. 



England. America. 



TJ. Llandeilo. Chazy. 



Sillery. 

 L. Llandeilo. Identical ? with — Levis. 



U. Calciferous. 

 U. Tremadoc. L. Calciferous.. 



L. Tremadoc. U. Potsdam. 



TJ. Lingula flags. L. Potsdam. 



L. Lingula flags. Identical with — St. John's Group. 



If the Lower Llandeilo and the L^vis formations be of the same age, 

 then the Tremadoc and Upper Lingula Flags must have been deposited 

 during the same interval of time with the four American formations 

 between the Levis and the St. John's Group. This appears to be all we 

 can say about them at present. When we undertake to parallel them with 

 each other we find there is a great difference in the grouping of the fos- 

 sils. Thus in the Ldvis we have quite a colony of trilobites belonging to 

 the same group with those that Mr. Salter .has placed in the genera Cono- 

 coryphe and Bickelocephalus, none of which in his recent lists (in Mem. 

 Geo. Sur. G. B., vol. 3) are reported as occurring in the. Lower Llan- 

 deilo, although they abound in the Tremadoc and Upper Lingula beds. 



