256 rEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 8, 



evidence of the same kind, and the addition of the minute struc- 

 ture, as described by Dr. Dawson, whose observations have been 

 confirmed and added to by the highest British authority upon the 

 class of animals to which the form has been referred, leaves on my 

 mind no room whatever for doubt of its organic character. Objec- 

 tions to it as an organism have been made by Professors King and 

 Eowney ; but these appear to me to be based upon the supposition 

 that because some parts simulating organic structure are undoubtedly 

 mere mineral arrangement, therefore all parts are mineral. Dr. 

 Dawson has not proceeded upon the opposite supposition, that be- 

 cause some parts are, in his opinion, undoubtedly organic, therefore 

 all parts simulating organic structure are organic ; but he has care- 

 fully distinguished between the mineral and organic arrangements. I 

 ■am aware, from having supplied him with a vast number of specimens 

 prepared for the microscope by the lapidary of the Canadian Survey, 

 from a series of rocks of Silurian and Huronian, as well as Lauren- 

 tian age, and from having followed the course of his investigation 

 as it proceeded, that nearly all the points of objection of Messrs. 

 King and Rowney passed in review before him prior to his coming 

 to the conclusions which he has published ; and his reply to these 

 objections forms a part of the succeeding paper. 



APPEIS^DIX. 



Ascending Section of Laurentian Hocks in the County of Hastings, 

 Canada West. Py H. G. Yenn^oe, Esq. 



1. Eed felspatbic strata, composed chiefly of red orthoclase, colourless 

 quartz, and grey or greenish-grey hornblende, rimning in streaks in some 

 places. The greater part of the mass is coarse-grained ; but there occur in 

 it occasional interstratified bands of a pale flesh-red, which are finer in 

 grain ; red haematite in streaks, and iron pyrites in crystals, are more or 

 less scattered through the mass, which has a probable thickness consider- feet, 

 ably over 5000 



2. Dark-green chlorite slates, associated with masses of greenstone and 

 actinolite-rock, probably in lenticular patches, and interstratified with 

 occasional beds of magnetic iron-ore, of which the Seymour bed, thirty feet 

 thick, is one. Bands of pale flesh-red felsite, or petrosilex, are of occasional 

 occurrence in the mass ; and garnets characterize some parts of the chlorite 

 slates 200 



3. Whitish highly crystalline limestone, interstratified with three bands 

 of tremolite, and with grey and pinkish dolomites, weathering drab or 

 some shade of yellowish-grey, presenting beds of from fifteen to forty feet 

 in thickness. Where the limestone adjoins the greenstone of No. 2, the 

 limestone becomes charged with grains of quartz, and more or less inter- 

 stratified with bands of quartz and siliceous or micaceous slates. When 

 the dolomite and greenstone adjoin, the dolomite presents thin layers or 

 segregated veins, composed of calcspar, bitter spar, and small crystals of 

 hornblende, which are characterized occasionally by the occurrence of 

 copper-pyrites, and, on the eighteenth lot of the fifth concession of Madoc, 

 by the presence of gold in considerable quantity, the three-inch belt in 

 which it is enclosed being flanked on each side by soapstone, of which there 

 are occasional beds in the upper part of the mass, some of them four feet 

 thick 2200 



4. Grrey siliceous or fine micaceous slates, fit for whetstones, with an 

 interstratified mass of yellowish white dolomite, weathering yellowish 



