CHAMBERS'S INFORMATION FOR THE PEOPLE. 



Lignite is a less hard variety of coal ; and the jet, 

 which is only a crystallised coal, yields the beauti- 

 ful jet of Whitby, so much used for ornaments. 



Organic Remains. The remains of plants and 

 animals are so abundant, that their enumera- 

 tion and description would fill volumes, and we 

 -can merely roughly indicate some of their wonder- 

 ful forms. 



Vegetable life was abundant, requiring a warm 

 climate like that of Australia. We find sea- 

 weeds, beautiful tree-ferns, lily-like leaves, palms 

 Bike the pandanus, and pines like the araucaria 

 and yew. The clays that occur were the very 

 soil on which those ancient forests grew, and in 

 -some of them, known as ' dirt-beds,' the roots are 

 seen in natural position, with part of the trunk 

 broken over, while the tree itself lies close by, as 

 if cut down by the woodman but yesterday. 



The animal remains are abundant and remark- 

 able. We find sponges, exquisite star-corals, 

 beautiful encrinites, sea-urchins, worms, and lob- 

 sters. The shells are very beautiful and varied, 

 <he most remarkable being the ammonite, of which 

 there are one hundred 

 and thirty species, and 

 the nautilus. Gigantic 

 cuttle-fish floated and 

 spread their black ink 

 through the oolitic seas. 

 Fishes were numerous 

 and large ; huge plated 

 sharks devoured their 

 prey, their very names 

 telling terrible things, 

 such as ' strong-tooth,' l 

 'star-spine,' 2 and 'great- 

 Ammonite. jaw.' 3 Tortoises also 

 floated on the summer 

 seas. 



But the most striking remains are those of 

 reptiles, so numerous, strange, and uncouth, that 

 the Oolite has been designated the 'Age of 

 Reptiles.' We find enormous skeletons, some 

 of them thirty feet long, of large lizards and 

 crocodiles, as of the Ichthyosaurus* or Fish-lizard, 

 all being more or less strange and terrible. 



In these rocks, too, a most interesting discovery 

 has lately been made, that of the earliest feathered 

 creature a real bird in which the bones, claws, 

 and full-spread plumage are finely seen. The 

 remains of warm-blooded animals have also been 

 found, especially of a kind of pouched creature 

 like the kangaroo. 



Scenery. The scenery and animals of the Oolitic 

 Period resemble, to a remarkable extent, those of 

 Australia, both in vegetable and animal remains. 

 The land and water went through many changes 

 during this long period. In the Lias times, the 

 seas were deep and tranquil ; under the Oolite, ex- 

 -posed coral beaches were dashed by great breakers, 

 that have left their work in broken shells and marls ; 

 while the Wealden seems to have been the carried 

 -deposits laid down in the estuary of a mighty 

 fiver, that rolled into the sea in what is now the 

 south of England ; and the present icy lands of 

 the arctic regions were covered with the vegeta- 



1 Pytnodnf, from Greek pycnos, strong, and odous, a tooth. 

 8 Asieracanthtu, from Greek aster, a star, and acanthos, a 

 pine. 



3 Eugnathus, from Greek eu, well, and gnathos, a jaw or thorn. 

 From Greek icJttkys, a fish, and sauros, a lizard. 

 30 



tion of a warm climate, which now appears as 

 Oolitic coal strata. 



IX. CHALK OR CRETACEOUS SYSTEM. 



Immediately above the Oolite lies a system in 

 which the chief rock is the well-known substance 

 chalk, and which has hence received the name of 

 the Chalk, or, what is the same thing, Cretaceous^- 

 System. In this system, other rocks also occur 

 namely, chalk-marl or blue clay, known by the 

 local name of Gault or Colt; thick beds of green- 

 coloured sand, called Greensand; and, imbedded 

 in the chalk, nodules of flint, which, when less 

 pure, is called Chert;"* and coal, in Vancouver's 

 Island. The chalk is used for many purposes : 

 when it is burned, it forms a useful lime ; when 

 hard enough, is used for building-stone ; and 

 when crystallised, forms a fine white marble. 

 The flints are an important ingredient in china, 

 porcelain, and glass, and from the sands we obtain 

 fuller's-earth. The whole system has been gener- 

 ally divided into two groups, the upper being 

 called the Chalk, and the lower the Greensand. 



Organic Remains. The plant-remains are 

 rare and imperfect, and seem to have been all 

 drifted. Leaves of different kinds, palms, fruits, 

 cones, and bits of pines have been discovered. 

 Animal remains, however, are very numerous, 

 and most beautifully preserved. We find sponges, 

 corals, sea-urchins complete in form and struc- 

 ture, beautiful star-fish, numerous crustaceans, 

 and varieties of the lobster tribe. The shells are 

 plentiful, and exquisitely beautiful in form and 

 even in colouring, and are the finest fossil preser- 

 vations found in any system. They include splen- 

 did ammonites and nautiluses, and hundreds of 

 other species, whose mere names would fill pages. 



Chalk Fossils. 



i, Plagiostoma spinosum; 2, Hamites intermedius; 3, Galerites 

 albogalerus ; 4, Scaphites striatus ; 5, Belemnites mucronatus. 



Fishes are not numerous, but are well preserved, 

 and, as in other systems, are named from peculi- 

 arities in form or structure, such as the ' twisted- 

 tooth,' 3 the 'wrinkle-tooth,'* 'thick-tooth,' 6 and 

 such like. Reptiles are also found similar to 

 those in the Wealden. Bones of birds have been 

 discovered, as also bones of what seems to be a 

 species of monkey. 

 Scenery. The Chalk series appears to be 



1 From Latin creta, chalk. 



2 Irish ceirthe, stone ; Welsh cellt, flint 



s Gyredus, from Greek gyros, a twist, and odous, a tooth. 



4 Ptychodus, from Greek ptyctos, a wrinkle, and odous, a tooth. 



5 Pycnodus, from Greek pycuos, thick, and odous, a tooth. 



