ARTHROPOD A—MYRIOPOD A. 



417 



Class MYRIOPODA Ruthe. 



The Myriopods (thousand-legs, centipedes) are air-breathing 

 (tracheate) arthropods, of worm-like appearance, with a distinct 

 head furnished with one pair of antennae and three pairs of jaws, 



Fig. 



1719. PaliBocampa anthrax. A myriopod from the coal measure nodules a 

 MazDn Creek, 111., showing legs and bristles, X 2- (After Scudder. ) 



and with numerous similar body segments, each of which is fur- 

 nished with a pair of legs (Chilopoda) or with two pairs of legs 

 (Diplopoda). 



The Palaeozoic Myriopods (ArchipolypodaRndProtosyngnatha) 

 begin, so far as known, in the Devonic, having been found in the 

 Old Red sandstone of Scotland and the Devonic (?) sandstones of 

 New Brunswick (Matthew). They are not uncommon in the 



Fig. 1720. Acantherpestes major. An almost complete individual, showing legs 

 on upper side of fossil and the branching spines on the lower, one half natural size. 

 Above is shown one of the small disks which cover the surface of the whole fossil 

 excepting the legs, X I- (After Scudder. ) 

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