172 Wisconsin Academy of Sciences, Arts , and Letters. 
EXPLANATION OF PLATE XVIII. 
4 a, Arrenurus securiformis Piers., dorsal view. 
b, Arrenurus securiformis Piers., epimera. 
c, Arrenurus securiformis Piers., lateral view. 
5 a, Arrenurus cardiacus nov. spec., dorsal view. 
b, Arrenurus cardiacus nov. spec., ventral view. 
c, Arrenurus cardiacus nov. spec., lateral view. 
6 e, Arrenurus paralleilatus nov. spec., 4th leg. 
9 a, Arrenurus conicus Piers., dorsal view. 
b, Arrenurus conicus Piers., ventral view. 
c, Arrenurus conicus Piers., lateral view. 
d, Arrenurus conicus Piers., 4th leg. 
