PLATE IX 

 TRIARTHRUS (PAGES 213-219) 



FIGURE 1. Triarthrus Becki Green ; dorsal view; showing character 

 and extent of antennules and limbs beyond the carapace. X 2^. 



FIGURE 2. Triarthrus Becki Green; ventral view; showing entire 

 series of appendages, together with hypostoma, metastoma, and anal 

 opening. X 2J. 



Utica Slate, Ordovician, near Rome, New York. 



