" the most complete and decided form, and it is one of the latest 

 of the group, as it commences in the Trias." He also says : "The 

 links between these coal-measure forms and those of r 



Fig. 3.— Ceratiocaris (Tpper Silurian). Fir,. . 

 5.— Dithyrocaris (Carboniferous). (Fig. 6.— Ar^.,., 



are many of them wanting ; but in Nebalia we have a good rep- 

 resentative of the compact, shield-shaped form of Ceratiocaris 

 the two valves soldered into one, and the rostrum attached, the 



