APPENDIX. 677' 



the belief that these curious turms may be fossils. The ligure represents a 

 somewhat perfect example, selected from a series of specimens kindly sent 

 to me by H. Poole, Esq., from the beds overlying one of the Coal-seam.s 

 at Glace Bay, Cape Breton. Previously to the receipt of these specimens, 

 I had thought little as to the origin of these forms, but a careful study of 

 Mr Poole's specimens led me at the time, in exhibiting them to the Natural 

 History Society of jMontreal, to state my belief that they are produced by 

 " concretionary action proceeding from the surface of a bed or layer, and 

 modified by the gradual compression of the matei'ial." Subsequently, at 

 the Meeting of the American Association at liurlington. Professor Marsh 

 of Yale College, in the course of an able dissertation on the origin of the 

 so-called " Lignilites or Ejysomites,^^ incidentally referred to the " Cone-in- 

 cone," and attributed it to the same cause, though unaware at the time 

 that tins explanation had occurred to any other person. 



Taking tliis view of the origin, these concretions serve as an interesting 

 illustration of the curious imitative forms sometimes assumed by concretions, 

 and also of the twofold movement of particles of matter in sediments under- 

 going consolidation under the double influence of mutual attraction and 

 of mechanical compression. Farther examples of the eftects of these forces 

 may be found in the formation of ordinary nodules, the infiltration of the 

 cavities of fossils, the slickensiding of underclays and other beds full of 

 vegetable matter, by the giving way of the latter under pressure, and the 

 curious crushing of erect jointed stems of Calamites into rows of disc-like 

 bodies, representing the firm nodes, while the intermediate portions have 

 collapsed (see figs, at pp. 150 and 406). The remarkable distortion of fossils 

 by pressure already referred to (p. 499), the nodular changes, and curious 

 minute crumplings which have taken place in the production of slaty struc- 

 tures, are also illustrations of that mobility of particles in consolidating 

 rocks, which must be invoked to explain the Cone-in-cone. 



Cone-in-cone is found in the Coal-formation rocks of other countries than 

 Nova Scotia, being not infrequent in the clay ironstones of England. It 

 is noticed by Professor Rogers and Professor Hall as occurring in the 

 Devonian of Pennsylvania and New York, and I have observed it in one of 

 the layers of fine laminated shale in the primordial strata of St John, New 

 Brunswick. 



