258 PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Probably there are undiscovered fossils in the sedimentary rocks 

 of New York ; but since an eager, enhghtened, and extensive search 

 has been going on for many years in districts both wild and under 

 cultivation, and abounding in large and lofty sections, very great 

 accessions cannot now be expected. James Hall will, however, soon 

 favour us with many more Devonian Zoophyta and Bryozoa. 



The relations between the sedimentary strata and their fossils are 

 close. They at once tend to demonstrate the gradual burial, at all 

 ages of growth, of the beings who lived on the spot, and to confirm 

 in detail the great law announced some years ago by Constant 

 Prevost, and very recently enforced by Agassiz *, that the Creator 

 has always placed organic forms among physical conditions suited to 

 their natures. The lower existences were intended to serve the 

 higher. The habitation was prepared for the living sentient 

 creature — not the creature for the habitation. To the sedentary 

 animal was given the solid support of a rock; to the burrowing 

 invertebrate, a loose sand ; and so on. Fine examples of this abound 

 in aU palaeozoic areas : those of New York and elsewhere will be 

 mentioned in the sequel. Murchisonf says that in certain arenaceous 

 tracts of Eussia, as also in the Scottish Old Red Sandstone, the 

 organic remains are exclusively those of fish — locomotive, of course, 

 and mostly carnivorous ; but in calcareous districts of the same age 

 similar fish are associated with molluscs, &c., the latter being only 

 there able to exist. In like manner the sandstone of Marwood, in 

 North Devon, contains a peculiar bed of the arenicolous CucuUcea 

 and Cyjpricardia, because it was only on such beds that they could 

 exercise their instincts ; and in the slaty and gritty layers of Pilton 

 and Brushford lie some remarkable Trilobites, together with the 

 Spirifer calcaratus, not seen, or rarely, in the neighbourhood (John 

 Phillips). A curious negative influence is exerted by serpentine in 

 the cliffs of the islands about the Lizard Point, and in the JSgean Sea. 

 In those local waters there is an almost total absence of Testacea, 

 while the adjacent bays, with sides of marble, abound in animal hfe. 

 Lake Superior, in like manner, possesses but few molluscs — chiefly 

 on account of the very httle limestone existing in the country the 

 drainage of which it receives. But this want is supplied on the 

 north side of the Lake by the great northern drift of Upper Silurian 

 limestone, which is scattered far and wide, and has furnished mate- 

 rials for the calcareo-argillaceous silt which, with the debris of 

 shells, now forms the bottom of Lake Superior. In parts where 

 this drift is deficient, some of the freshwater molluscs, being lithodo- 

 mous, are coated with a mosaic of very small bits of quartz and 

 felspar. The influence of the mineral character of the sediment is 

 conspicuously seen in the nature of the vegetable food and the 

 shelter it provides — both acting in a marked manner on the number 

 and kind of the animals, carnivorous and herbivorous, who dwell 

 there. 



"We now present two Tables of great interest (Tables Y. and YI.), 



* Contributions to the Natural History of the United States, 

 t Greol. of Russia, &c., vol. i. p. 58L 



