The Era of Invertebrates 



though in spite of this bulk it is quite possible 

 that neither would have been a match for the 

 giant crab of Japanese waters, or even for one 

 of the big overgrown lobsters that now and 

 then is taken by our New England lobstermen. 

 Like the trilobites, the nearest existing relatives 

 of these eurypterids are the king crabs, al- 

 though they have some points of resemblance 

 to scorpions, and the Rev. Mr. Hutchinson has 

 dubbed them sea scorpions. One of the pe- 

 culiarities of these animals consists in having 

 what are really the mouth parts modified for lo- 

 comotion, so that the same jointed appendages 

 served for walking or swimming, capturing the 

 animals on which they fed, and devouring their 

 prey after it had been taken. 



In the Carboniferous j)eriod the eurypterids 

 came to an end, and the trilobites and brachio- 

 pods fell oif greatly in species, as did other 

 groups of invertebrates. But this disappear- 

 ance of animals once so prominent among living 

 things must not be looked upon as a real loss, 

 but as a part of the general progress of life, 

 the replacement of some animals by others 



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