Febeuaey 12, 1897]. 



SGIENGE. 



253 



brachiopods, and of Jackson on echinids 

 and lamellibranchs. In conclusion he ap- 

 pealed for a consideration of evolutionary 

 geology against both catastrophism and 

 uniformitarianism . 



Sir W. Dawson's paper on ' Pre-Cambrian 

 Fossils,' was of so much interest that we 

 give his own abstract in full ; the paper 

 was illustrated by a very beautiful series of 

 lantern slides. 



The author stated that it was his object 

 merely to introduce the specimens he pro- 

 posed to exhibit, by a few remarks ren- 

 dered necessary by the present confusion in 

 the classification of pre- Cambrian rocks. 

 He would take those of Canada and New- 

 foundland as at present best known, and 

 locally connected with the specimens in 

 question. 



He referred first to the ' Olenellus Zone,' 

 and its equivalent in New Brunswick, the 

 ^ Protolenus Fauna ' of Matthew, as at 

 present constituting the base of the Cam- 

 brian and terminating downward in barren 

 sandstone. This Lower Cambrian had in 

 North America, according to Walcott, af- 

 forded 165 species, including all the leading 

 types of the marine invertebrates. 



Below the Olenellus Zone, Matthew had 

 found in New Brunswick a thick series of 

 red and greenish slates, with conglomerate 

 at the base. It has afforded no Trilobites, 

 but contains a few fossils referable with 

 some doubt to Worms, MoUusks, Ostracods, 

 Brachiopods, Cytideans and Protozoa. It is 

 regarded as equivalent to the Signal Hill 

 and Random Sound Series of Murray and 

 Howley in Newfoundland, and to the 

 Kewenian, and the Chuar and Colorado 

 Canyon Series of Walcott in the West. The 

 latter contains laminated forms apparently 

 similar to Cryptozoon of the Cambrian and 

 ArcJueozoon of the Upper Laurentian. 



The Etcheminian rests unconformably on 

 the Huronian, a system for the most part 

 of coarse clastic rocks with some igneous 



beds, but including slates, iron ores and 

 limestones, which contain worm-burrows, 

 sponge-spicules, and laminated forms com- 

 parable with Cryptozoon and Eozoon. The 

 Huronian, first defined by Logan and Mur- 

 ray in the Georgian Bay of Lake Huron, 

 has been recognized in many other locali- 

 tieSp both in the west and east of Canada 

 and the United States ; but has been desig- 

 nated by many other local names, and has 

 been by some writers included, with the 

 Etcheminian and sometimes with part of 

 the Laurentian, in the scarcely defined 

 'Algonkian ' group of the United States 

 Geological Survey. 



Below the Huronian is the Upper Lau- 

 rentian or Grenville system, consisting of 

 gneisses and schists (some of which, as 

 Adams has shown, have the chemical com- 

 position of Palaeozoic slates), along with 

 iron ore, graphite and apatite, and great 

 bands of limestone, the whole evidently 

 representing a long period of marine depo- 

 sition, in an ocean whose bed was broken 

 up and in part elevated before the produc- 

 tion of the littoral elastics of the Huronian 

 age. It js in one of the limestones of this 

 system that, along with other possible fos- 

 sils, the forms known as Eozoon Canadense 

 have been found. The author did not pro- 

 pose to describe these remains, but merely 

 to exhibit some microphotographs and slices 

 illustrating their structure, referring to 

 previous publications for details as to their 

 characters and mode of occurrence. 



Below the Grenvillian is the great thick- 

 ness of Orthoclase gneiss of various tex- 

 tures, and alternating with bands of horn- 

 blende schist, constituting the Ottawa gneiss 

 or Lower Laurentian of the Geological Sur- 

 vey. No limestones or indications of fossil 

 remains have yet been found in this funda- 

 mental gneiss, which may be a truly primi- 

 tive rock produced by aqueo-igneous or 

 ' crenitic ' action, before the commencement 

 of regular sedimentation. 



