[DAWSON] FOSSIL srONGES AND OTHER OrtGANIC REMAINS 



93 



natural facts which underlie them, to the publications named in the foot- 

 note to this section.' f < 



& 



lys 



II. — Subdivisions ov the liuEHEc Giioui'. 



Confining ourselves to the sections on the south whore of the Lower 

 St. Lawrence, the subdivisions, as worked out by Logan and Jtichardson 

 and more recently by Klls, with the aid of Whitea\'»'H in regard to the 

 Trilobites, Bi-achiopods, etc., and of Lapworth'^ and Ami in the grapto- 

 litic fauna, may be stated as follows in ascending order : ' 



1. The Sillery Si'/'ies, seen at the Chaudi6re Eiver, near Quebec, and 

 also at Matane and Cape Rosier, as well as at Little Mdtis. Among its 

 characteristic fossils are the little brachiopod Obolella (Linnarssonia) 

 pretiosa, Billings, and Dldyoncma saciale. of Salter {D . flabellare of Eich- 

 wald), also species of Bryo(jraptiis and Clonoijraptus. The prevalent 

 rocks are grayish sandstones anil conglomerates with shales of red, gray 

 and black colours, and more rarely bands of limestone and dolomite. It 

 may be regarded as the base of the Quebec Group proper, and as the 

 equivalent of the Calciferous of more western districts and of the Tremadoc 

 of Wales, and perhaps as the highest member of the Cambrian system. 



2. The Levis Series ; to which belong the shales, limestones and 

 conglomerates exposed at Levis, opposite the city of Quebec, and which 

 has been recognized as far east as Ste. Anne des Monts. Its most charac- 

 teristi • fossils are graptolites of the genera Phylhnjraptus, 'Tetnujraptus, 

 etc., most of which are described by Hall in his classical monograph on 

 this fauna ; while its Trilobites, etc., have been studied by Billings, and 

 catalogued by Ami, who separates the fossils found in boulders in the 

 conglomerate from those properly belonging to the formation.* This 

 series is in the horizon of the Upper Calciferous and Chazy, and may be 

 regarded as equivalent to the English Arenig and Skiddaw. 



3. The Marsouin Series ; found at that place and at Griffin Cove, 

 White Hiver, and elsewhere, and heading graptolites of the genera Diplo- 

 graptus, Cmioyraptus, etc. It is apparently of Chazy-Trenton age and 

 equivalent to the English Bala. 



4. Still higher beds holding Biployraptus pristis and other forms 

 characteristic of the Utica shale, and therefore newer than the Quebec 

 Group proper, occur west of Marsouin River, near Tartigo River and 

 elsewhere. At this period, owing to the subsidence of nor'.hern land, the 



' Appendix to Harrington's Life of Sir William Logan, p. ^XA et aeq. ; On the 

 Eozoic and Palflaozoic Rocks of Eastern Canada, .Tournal London Geol. Society, 1888 ; 

 The Quebec Group of Logan, Canadian Record of Science, 1890 ; Salient Points in the 

 Science of the Earth, 1894. 



* Transactions Royal Society of Canada, 1886. 



* For notices of previous work and recent discoveries, see Report by Ells, Geolo- 

 gical Surrey of Canada, 1887-88. 



* Report Geol. Survey of Canada, 1887-88. 



Sec. IV., 1896. 6. 



