1258 



XEW YORK STATE MUSEUM 



PLATE lO 



Hughmilleria socialis sp. nov. 



Page 1091 



1-6 Cephalotkoraces of individuals of various ages, showing 

 slight variations in outline and in the position of compound eyes. 

 Natural size 



Eurypterus pittsfordensis sp. nov. 



Page 1098 



7 Upper view of appendages of cephalothorax. Shows the en- 

 dognathites in position, with their clawlike terminal joints, and 

 the gnathobases of the swimming feet. Natural size 



Hughmilleria socialis sp. nov. 



Page 1091 



8 Two gnathobases of swimming feet. Natural size 

 1) Coxal joint of endognathite. x3 



