74 THE CANADIAN NATURALIST. [Vol. viL 



Prof. Marsh has well explained another phase of the influence 

 of hard bodies in producing partial slicken-sides, in his paper on 

 StyloUtes, read before the American Association in 1867, and 

 the application of the combined forces of concretionary action 

 and slicken siding to the production of the cone-in-cone concre^ 

 tions, which occur in the Coal-formation and as low as the Pri- 

 mordial, was illustrated by the author in his Acadian Geology^ 

 p. 676. 



Of course, as I have not seen the specimens referred by Prof. 

 Geinitz to Gulielmites, but only the figures in his Memoir on 

 the Permian plants of Saxony, I cannot offer any decided opinion 

 as to their nature; but I have little doubt that the bodies 

 mentioned by Mr. Carruthers are of the kind above referred to^ 

 and would be found to have had a solid nucleus either organic 

 or of some other kind. 



I may remark in conclusion that it would be well if collectors 

 would give some attention to imitative markings and animal 

 footprints of the kinds above referred to, as well as to their mode 

 of occurrence with reference to the surfaces and material of the 

 beds on which they are found. The labors of Duncan, Hitch- 

 cock, Jardine, Salter, and other careful observers, show how^ 

 much interesting information may thus be obtained, and many 

 mischievous errors might also be avoided. In my own studies 

 in fossil botany, I have made it a point to collect and study all 

 markings resembling plants, as well as the effects of crumpling,, 

 pressure, concretionary action, cyrstalization, shrinkage and 

 slicken-siding upon actual vegetable remains ; and by so doing I 

 have avoided the trouble and expense of describing and figuring 

 some dozens of imaginary species; while it would be easy to 

 point out in works of some pretension costly figures and elabo- 

 rate descriptioDs based on imitative forms or distorted and other- 

 wise altered fossils. 



