294 Dr. H. Woodward — The Position of the Merostomata. 



Fore-body or 



cephalon with its 



appendages. 



Sixth pair 

 (swimming feet). 



1-6, segments of mid-bod \ < 



1-6, segments of hind-body 

 they have no appendages 



Compound eyes. 

 Larval eyes (ocelli). 



Tail-spine or telson. 



Fig. 1. Upper or dorsal aspect of Eurypterus Fischer i, from the Upper 

 Silurian of Oesel in the Baltic. The drawing made from G. Holm's 

 original figure. Nat. size. Eeproduced by permission of the Trustees 

 of the British Museum (Natural History). 



