300 



THE WOIU/D. 



dragon-fly, and the house-fly. Among the moluscs, or soft 

 bodied animals, we find one very common and characteristic of 

 this period, but now entitely extinct, it belongs to the same fami- 

 ly cephalopoda, i. e. having the arms or feet near or upon the 

 head, ns the nautilus, and is called the ortlwcerai itc, or straight 

 horned animal and is figured below, nothing is known of these 





except the fragments of their former habitations, some of them 

 are slender and pointed, others nearly straight, and they are oc- 

 casionally found of great size. Such were the inhabitants of 

 the globe during its early periods, while yet no fishes swam in 

 its waters, or animals roved in forests upon the shore. Trilobites 

 swarmed in innumerable multitudes; the crinoidal animals were 

 attached to every fragment of rock; and the voracious cephala- 

 poda roamed through the deep. Day and night then as now suc- 

 ceeded each other, and year after year passed on, but who can 

 tell, or who can estimate the ages which rolled away from the 

 commencement of the period we have been considering to the 

 close of those immense deposits called the Silurian. But the 

 dawn of a new era was now commencing, and the great and im- 

 portant natural class of fishes were about to be introduced, though 

 with such marked peculiarities and singular forms, and so differ- 

 ent from any now living that they almost seem allied to the crus- 

 taceans, or to the reptiles. One of the most singular, with 

 long bony fins, is called the PtcricklJnjs Cornutus, or horned wing- 

 ed fish. It was of small size, the head and body being covered 

 with strong plates of bone coated with enamel. Another singu- 

 lar fish called Cephalapsis, or buckler-headed, possessed an enor- 

 mous buckler head, similar to the cephalic shield of certain trilo- 

 bites. It bus been compared, and not unaptly, to the crescent 

 shaped blade of a saddler's cutting knife, as will be seen on ref- 

 erence to the engraving on the following page. 



There are many other varieties or groups of fishes belonging 



