SECT. XIV 



THE EURYPTERID.E 



245 



sensory. From our point of view, according to which 

 the large rowing Hmbs belong to the first trunk seg- 

 ment, we should have had to conclude that one pair of 

 limbs had disappeared. Such a supposition is however 

 not necessary, as F. Schmidt has found and described 



Yic. 56.— Eurypterus Fischeri Eichw. : Upper Silurian, natural size, after F. Schmidt 

 (froni Zittel's Haiidbuch der Palcrontologie). Between the first pair of feet, 

 Schmidt found a fine pair of feelers, corresponding with the Antennules of the 

 other Crustacea. 



a pair of rudimentary antennae between the first pair, 

 so that Eurypterus possesses the typical number of 

 head appendages. It is a fact generally accepted that 

 the pair of large rowing limbs corresponds with that 

 of the sixth segment. There is, however, no general 

 agreement as to whether these first six segments form 



