TJie Royal Society of Canada. 431 



reclaiming of the Huronian in its various geographical 

 groups from the more distinctly crystalline complex rocks 

 which may properly be called Archsean. The rocks of the 

 Archaean complex thus simplified by the removal of the 

 Huronian, are next considered in the light of observations 

 made by the writer in the Lake of the "Woods and Rainy 

 Lake regions, and the origin of the rocks commonly called 

 Laurentian, together with their age relatively to other 

 rocks of the Archsean complex, is discussed. 



In <: Rock Stretching," by the same author, the writer 

 refers briefly to the interesting observations and conclusions 

 of Lehmann, Baltnzer, Eeusch and other investigators in 

 Europe on the phenomena of the stretching and squeezing 

 of crystalline rocks under the enormons pressures which 

 have effected the folding of the earth's crust. Instances of 

 stretching are described in rocks from the Rainy Lake 

 region as observed not only in the field, but also, more par- 

 ticularly, in thin sections, under the microscope. Diabases 

 and quartz-porphyries are dealt with more especially, and 

 examples of the shattering and tearing asunder of their con- 

 stituent minerals are given. An attempt is also made to 

 reduce to measurement the extent to which such stretching 

 may go without the complete obliteration of the original 

 structure of the rock. 



In a communication " On the Classification of the 

 Trilobites," Professor. E. J. Chapman, proposes a new 

 grouping of these indistinct crustaceans ; one based essen- 

 tially on structural in place of stratigraphic affinities. Since 

 the very general rejection of Barrande's classification — the 

 leading subdivisions of which are based on a single special 

 character — stratigraphic considerations have unduly in- 

 fluenced, it is contended, the proposed collocations of these 

 types. Many forced and arbitrary groupings have thus 

 been made ; and forms, on the other hand, closely related 

 by general structure, have been widely separated. Lines 

 of evolutionary descent, where traceable, become thus 

 obscured. In the proposed classification, four leading sec- 

 tions, with thirteen groups and twenty-three families, are 

 adopted. 



