UPPER SILURIAN. 



239 



pleuroptyx H., near Fig. 254 on page 174. Ostracoid crustaceans of 

 large size, like Fig. 473, are abundant in some layers of the Water- 



Figs. 459-470. 

 461 



BRACH,OPO D s.-Fig. 459, Hemipronites radiata ; 460, 461, Rhynchonella ventricosa; 462, 463 

 Penta m erus galeatus; 464, 465, P. pseudo-galeatus ; 466, Eatonia singular-is ; 467, Meristella 

 sulcata ; 468, Orth,s vanca ; 469, Spirifer macropleura ; 470, Meristella levis. 



lime. Besides these Crustaceans, there was also a new kind, here 



making its first appearance in Amer- 

 ican rocks. One species of the group 

 is the Eurypterus remipes of Dekay 

 (Fig. 474). Unlike Trilobites, it 

 has large jointed arms, and a body 

 which resembles that of the Sap- 

 phirina and Caligus groups of mod- 

 ern Crustaceans. (Figs. 165, 166, 

 on page 120, represent the female 

 and male of a Sapphirina from ex- 

 isting seas.) Many specimens of 

 this kind of Crustacean from the 

 Water-lime have a length- of a foot 

 or more. 



Figs. 471-474. 



Figs. 471, 472, Tentaculifces irregularis ; 473, 

 Leperditia alta ; 474, Eurypterus remipes. 



