208 



H. Greyish-blue limestones, 265 



G. Dark grey limestones, 400 



F. Dark grey geodlferous limestones, 500 



E. Dark grey limestones, 500 



D. Magnesian limestones, 1 74 



1839 



Tliese five divisions (D to H inclusive) represent the Calciferous 

 formation. 



POTSDAM GROUP. 



C. Quartzites, limestones, dolomites and blackish-bUie soft shales, 932 



B. Quartzites, limestones, dolomites and micaceo-arenaceoiis shales, 483 



A. Blackish blue soft shale with quartzites in the upper half 605 



2020 



8620 



In this table the thickness of the rocks, in all the divisions from A to G 

 inclusive, is given as ascertained at Bonne Bay, and for I, K, L, M and N 

 as measured at Table Head. The volume of the same strata in the region 

 further north is not so great. The Potsdam group at the Straits of Belle 

 Isle, for instance, is only 1147 feet in thickness, whereas at Bonne Bay 

 it is 2020, the difference being made up by a greater development of shale 

 at the latter locality. Divisions and P were measured at Cow Head, and 

 the greenish sandstones and red shales of Q at the south arm of Bonne Bay. 

 For further details relating to the structure of the whole region, fi*om 

 Bonne Bay to the Straits of Belle Isle, reference must be made to the 

 Geology of Canada. 



For a catalogue of the fossils and remarks on their distribution, see the 

 end of this article. 



Protozoa. 



Among the fossils collected in the limestones of the Quebec group, in 

 the northern part of Newfoundland, are fragments of several species 

 resembling, in their external characters, many of those of the Mesozoic 

 rocks, which are usually considered to be sponges. The specimens are 

 so imperfect that their internal structure cannot be determined with any- 

 thing like the precision required to decide upon their true position. They 

 appear to me, however, to differ from all the known genera, and I shall 

 therefore dispose of them provisionally, for the present, as follows : — 



Genus Calathium. (N. gen.) 



Generic characters. — The species for the reception of which this genus 

 is proposed, have a cylindro-turbinate form, and arc perforated by small 

 tubular canals, which are arranged in longitudinal and transverse rows, 



