THE CARBONIFEROUS PERIOD. 185 



ciated with the Coal, which have been deposited in lagoons, 

 estuaries, or marshes, in the immediate vicinity of the land, and 

 which actually represent an old land-surface. The Arachnids 

 are at present the oldest known of their class, and are repre- 

 sented both by true Spiders and Scorpions. Remains of the 

 latter (fig. 123) have been found both in the Old and New 

 Worlds, and indicate the existence in the Carboniferous period 

 of Scorpions differing but very little from existing forms. The 

 group of the Myriapoda, including the recent Centipedes and 

 Galley-worms, is likewise represented in the Carboniferous strata, 

 but by forms in many respects very unlike any that are known 

 to exist at the present day. The most interesting of these 

 were obtained by Principal Dawson, along with the bones of 

 Amphibians and the shells of Land-snails, in the sediment filling 

 the hollow trunks of Sigillaria, and they belong to the genera 



Fig. 123. Cyclophthalmus senior. A fossil Scorpion from the Coal-ineasures 

 of Bohemia. 



Xylobius (fig. 124) and Archiulus. Lastly, the true insects are 

 represented by various forms of Beetles (Coleoptera},Orthoptera 

 (such as Cockroaches), and Neur apterous insects resembling 

 those which we have seen to have existed towards the close of 

 the Devonian period. One of the most remarkable of the 



