108 



KNOWLEDGE ♦ 



[Feb. 1, 1886. 



Amtebea* 

 change). 



Foraminifera (Lat. foramen, 

 an opening). 



kingdoms, that there is no known fossil for which a new 

 sub-kingdom is required : — 



I.— PLANTS. 



Sea and other Water-weeds (^Z^«") J 



Licliens > Gymnospores, i.e. naked spores. 



Fnngi ) 



Mosses i 



Ferns and HorseUiils ' Angiospores, i.e. enclosed spores. 



Club Mosses ] 



Pines and Palm Ferns Gymnosperms, Z.^'. naked seeds. 



(many seed-lobes). 



Grasses, Sedges, Palms '\ 



(one seed-lobe) I . ■ . i i i 



Tree., Shrubs, Herbs ^ J Angicsperms,,,, -.enclosed seeds. 



(Iwo seed-lobes) ; 



II.— ANIMALS. 



1. Invertebrates, i.e. without backbone. 



Monera* (gr. moiios, single) Structureless, sticky, alike all over, 

 (gr. amoihf, | Slight unlikeness of parts ; always 



) changing shape. 



' Secrete shell or skeleton of lime 

 from water. Show passage to 

 further unlikeness in parts. 

 Polycystina(gr.7;()Z!«, many, ■ji Secrete shell or skeleton of flint 



and histis, a cyst) ) from water. 



Sponges. 



Coral-animals, anemones,* jelly-fish.f 



Sea-lilies, star-fish. 



Worms of all kinds. 



Crabs, spiders, centipedes, insects (Crustacea). 



Sea-squirts. (Ascidia) -^ Mollnqca 

 Oysters, snails, cuttlefish ) *io""sca. 



2. Vertebr.\tE8 ; — 



A. Pisces. 



Lancelet (Amphioxus). 

 Fish of all kinds. 



B. Aiiij)/iibia. 

 Toad, frog. 



C. ReptiUa. 



Serpent, lizard, crocodile, turtle. 



D. jU-es. 



Birds of all kinds. 



E. Mammalia. 



1. Aplacental (bringing forth immature young). Moiifi remes, 

 or une-vented ; duckbill ; spiny ant-eater. J/arsiij)iti!.i, or 

 j)Ouched ; kangaroo, opossum. 



2. Placental (bringing forth mature young): — Ant-eater, 

 manatee; whales and porpoises; horse and all other hoofed 

 animals ; elephant ; seal, dog, lion, tiger and all other flesh- 

 feeders ; hare and all other gnawing animals ; bats ; moles and 

 all other insect-feeders ; apes ; man. 



The following sub-divisions of the stratified rooks 

 indicate the order of their succession. There is no one 

 section of the earth's crust where a complete series is to 

 be found with layer superposed on layer like the skins of 

 an onion ; but whatever gaps exi.st locallj' do not aiiect 

 the relative age and place of each stratum which, as 

 noted above, are fixed by the fossils : — 



Epoch.J Systems. 



Archeolithic and Primary 



( Laurentian, Cambrian, Siluiian, 



Secondary or Mesozoic 



Devonian or Old Red Sandstone, 

 ( Carboniferous, Permian. 

 ( Triassic, Jurassic or Oolitic, Cre- 

 ^ taceous. 



Tertiary or Cainozoic Eocene, Miocene, Pliocene. 



Quaternary Or Post Tertiary . Recent (Pre-historic, Historic). 



Before passing to a rapid summary of the leading 

 fossil contents, it may be remarked that no uniform 

 principle has governed the choice of their system-names. 



* No fossils of these soft-bodied lowest forms exist. 



t Impressions of bodies only. 



j Vide Knowledge, January, p. 78. 



Sometimes they indicate the place where a system is 

 markedly developed, sometimes the typical features of 

 the system, but they are the accepted nomenclature in all 

 treatises on geologj', and are therefore adopted here. 



The Laurtntian rocks, vast and venerablest sediments 

 of primeval seas, are highly metamorphic. Heat, 

 moisture, and enormous pressure have changed their sand- 

 stones into sparkling crystalline rocks, their limestones 

 into veined and variegated serpentines. Formerly they 

 were cla.ssed as "Azoic "^I'.e., without life — but of late 

 years those which form the Laurentide mountains in 

 Canada, whence the general name of the series, have 

 acquired special interest from the discovery of certain 

 veined structures in them which, on balance of evidence, 

 are pronounced to be the remains of a marine animal, 

 very large of its kind, related to the group of the 

 Foraminifera, which possess the power of secreting lime 

 from the water, and forming therewith perforated shell- 

 coverings of exquisite symmetry and beauty. 



Certain members of these lowest life-forms might 

 smile at man's "claims of long descent," for they have 

 survived through the long and change-bringing millions 

 of years to this day, shedding their shells on the deep 

 ocean floor, as their ancestors shed theirs and built there- 

 with the vast chalk and limestone hills and mountain 

 ranges in relatively shallow seas. While some secrete 

 chalk, others secrete flint, among which last are the 

 minute plants kno wn as Diatoms, whose remains compose, 

 among other deposits, the " rottenstone " used as 

 polishing powder, with little thought on our part that 

 no less than forty-one thousand million .skeletons go to 

 make up a single cubic inch. 



Even if the organic character of EozoiJn Canadense 

 were disproved, and we do not witness in it, as its name 

 implies, the " dawn of life," abundant tr.ices remain that 

 the Laurentian waters teemed with living things. For 

 the limestones, the abundant graphites, and the great 

 beds of iron ore which occur in its rocks, are due to 

 the action of animal and plant life. 



The Canihrian rocks, which are less metamorphic, add 

 little to our knowledge of primitive plant-forms, such 

 as are preserved being probably Algte, or sea-weed, 

 corresponding to the tangles covering large areas of the 

 Atlantic, especially the Sargas.so Sea. But the system is 

 fairly rich in fossils of marine animals, themselves the 

 descend;intsof a long line of perished ancestors. Sponges, 

 sea-lilies, ;.nd low forms of mollusca or true shell-tish are 

 found; but the typical and most perfect fossil is that of 

 the three-lobed crustaceans called trilobite.s, which 

 swarmed in those ancient seas, and survived till the 

 Carboniferous period. 



The Silurian rocks, though exhibiting in crumiiledand 

 rugged mountain- chains the action of agents both above 

 and below the earth, are much less metamorphosed than 

 the preceding systems. They are in large measure the 

 worn fragments of land areas which stretched across 

 northern Europe for above two hundred miles into the 

 Atlantic, the sediment being deposited in a shallow sea 

 which then covered central and southern Europe, and the 

 floor of which was slowly raised as a primitive European 

 continent at the close of the Silurian period by sub- 

 terranean movements. The most interesting land fossils 

 are those of plants allied to huge club mosses, ancestors of 

 the o-icrantic forest-kings of Devonian and Carboniferous 

 times, while the marine remains are varied and numerous, 

 comprising seaweeds, foraminifera, corals, starfish, shell- 

 fish of every kind, trilobites, and with these huger lobster- 

 like crustaceans, sometimes measuring above six feet in 

 jength. 



