6 



found in these " Trias/' which are probably of the 

 marsupial or pouched order, allied to the Aus- 

 tralian kangaroo rats. Marine life predominated, 

 but reptile life was most maryellous in its form 

 and variety. Volcanic action is manifest in every 

 period. 



Jurassic. — The Jura Mountains between France 

 and Switzerland lend their name to the next great 

 system of rock deposit.which occupies large tracts 

 in both hemispheres, and ranges from the Arctic 

 Circle to Australia. Its strata, largely composed 

 of corals and other organic remains, are rich in 

 special life forms, which are limited to the secon- 

 dary epoch. Some people call this system the 

 Oolitic (an egg and stone), and there are those 

 who say that the oolitic rocks are masses of fishes' 

 roe ! Of course, this fallacy needs no contradiction. 

 The grains have grown from tiny shell particles 

 or fine sand, by the coatings of carbonate of lime 

 in solution in the water, and simply take the form 

 of eggs. In England there are several well-known 

 representations of this system. Bath district 

 furnishes a dozen sorts and very useful they have 

 been for building purposes. At the seaside, how- 

 ever, this stone soon decays. Portland stone, 

 another oolite, is a much better stone to withstand 

 the disintegrating effects of the elements, and 

 we see it to advantage in St Paul's Cathedral 

 and similar massive classical structures. Purbeck 

 marble is another oolite, formed of tiny shells, 

 and so bard that it takes a good polish, and has 

 for a thou3and years been in great demand for 

 slender shafts in our abbeys, our cathedrals, and 

 even in the Pagan fanes of our own land before 

 the days of the good missionary St. Augustine. 

 The Jurassic rocks hide remains of the most 

 gigantic creatures ever known ; it may be well 

 said *' there were giants in those days" — monsters 

 of the deep, in the ferocious sea lizards, with their 

 fish-like bodies and their flipper-like limbs. The 

 land, too, had its monsters, of such fearful size 

 and aspect, seen neither before nor since. Nearly 

 all of the lizard type, their names all end in 

 " saurus " (reptile). The largest example in this 

 country isprobably the Dinosaurrecently presented 

 to the South Kensington Museum by Mr. 

 Carnegie. It is indeed a monster, 84-t't. long 

 from bead to tail, found in America. Perhaps 

 the largest ever unearthed was one found about 

 ten years back in the Rocky Mimntains, a single 

 leg bone being ft. long ; the total length given as 

 130ft. ; it would require as much as was needed for 

 three oi dinary elephants for a substantial meal and 

 as his roar was calculated to be heard at least ten 

 miles away they called it Brontosaurus (thunder). 

 There were great flying lizards, partly birds and 

 partly reptiles, one called a " Pterodactyl," like 

 an immense bat, with sharp devouring teeth and 

 claws. It is in this system that the first true bird 

 is found, about the size of a rook ; it has no past or 

 present relative and was knowu by the name of 

 •'Arcbjenpteryx" (beginning of wings). 



Cretaceous. — The best known system isprobably 

 the Cretaceous (chalk). When the sea overspread 

 A large part of Europe, Asia, and North Africa, its 

 floor received the tiny shells of the foraminifera, 

 and converted them into chalk, flmts forming by 

 Btlioa gathering round any organic m>itter on the 



sea bottom. The thickness of the chalk in places 

 may be l.OOO feet, and it is supposed by some that 

 the quickest possible time for chalk to form out of 

 this ooze would be at the rate of one inch in four 

 hundred years, so that five million years would be 

 required to form the chalk alone. The chalk rests 

 on the upper greensand, and going downwards we 

 find the gault, the lower greensand, the Weald 

 clay, and the Hastings sand at the bottom of this 

 system. The gault is a blue clay, containing many 

 marine fossils. In the Folkestone Warren may be 

 fuund any number of the pencil-like terminals of 

 the Beleracite, a crustacean of the cuttle fish 

 group, with its eight long tentacles, and indis- 

 pensable ink bag. The spiral shell of the 

 ammonite is also found here in great abundance, 

 and takes its name from its resemblance to the 

 horns on the statue of Jupiter Amnaon. These 

 molluscs swarmed in the cretaceous seas and often 

 attained the size of a cart wheel. Eight through 

 this cretaceous system, the large saurians lived 

 and thrived ; immense reptiles have left their 

 marks on muddy fiats ; fierce birds with sharp teeth 

 and reptile-like brains swooped down upon their 

 prey, but beyond this point, the end of the 

 secondary epoch, this unwieldly class of animal 

 life does not appear ; they bad done their work, 

 man not requiring their help nor company. Fossil 

 remains prove their plentiful existence ; the order 

 changes, a great upheaval places the chalk above 

 the sea, the geography of Britain is vastly altered, 

 the secondary epoch has ended. 



Tertiaries — We now take a brief glance at the 

 third order of formation, known as the Tertiaries. 

 It is a help to remember the Tertiaries are the 

 layers above the chalk, and they are divided into 

 five systems, determined solely by the proportion 

 of shell flsh to existing species. Mollusca is the 

 key or alphabet to Palaeontology, and according 

 to the percentage of present-life found, so the 

 system is determined. The names chosen to 

 denote the systems are : — Eocene — Dawn of recent 

 species ; Oligocene — few recent species ; Miocene — 

 a minor proportion of recent specips ; Pliocene — a 

 major portion of recent species ; Pleistocene — few 

 or no extinct species. 



Eocene. — The London clay is a well-known 

 representative of the lower or Eocene system ; it 

 is a thick mass of grey or dark brown stiff clay 

 with nodules here and there of impure limestone, 

 and is marine throughout its whole extent from 

 Reading to Thanet, and from Alum Bay to Yar- 

 mouth. At this period nearly all of Asia and 

 Europe were covered by the sea, vast beds of lime- 

 stone and sandstone were laid down, the Sphinx 

 rock in Egypt was being formed, and these same 

 beds largely compose the Alps, Carpathians, Atlas, 

 and Himalayas, and lesser mountain chains. The 

 larger mountains have been formed since the 

 smatler,and simply have not been so worn down by 

 eroding agents. It was an age of great mammals, 

 and it is curious that in the London clay are found 

 more remains of turtles thnn are found in any 

 other part of the world. Among the fossils, the 

 most interesting, perhaps, is that representing 

 the ancestor of the horse, a creature about as large 

 as a fox, with five hoofed toes on each foot ; the 

 animal has since then grown larger, and fossils in 



