PLATE 70. 
Fig. 1. 672. 1. Lichas boltoni. (Pag. 311.) 
1 a. The head of an individual smaller than the preceding, in which the form of the eye tubercles is more 
distinctly preserved, as well as the form and direction of the lateral lobes of the glabella. 
1 b. The under side of the head and several articulations, showing the clypeus attached below the front of 
the glabella. 
1 c. A fragment of another specimen, showing the impression left after the removal of the clypeus. 
1 d. The under side of the glabella, where the clypeus is removed. 
1 e. Profile of the buckler, showing the elevation of the eye in a specimen where it is very well preserved. 
1 /. A fragment of the glabella and base of the buckler. 
1 g. A pygidium of a specimen of medium size, showing more pointed terminations of the articulations. 
1 g f. A portion of the crust magnified from 1 g. 
1 h. A smaller pygidium with the terminations broken. 
1 i. A young individual of this species, having the base of the buckler broken. 
Fig. 2. 674. 1. Arges phlyctanodes. (Pag. 314.) 
2 a. The posterior part of the buckler, showing the lateral lobes and the prominent central one. 
2 b. The front of the same, a view directly opposite to the previous one., 
2 c. Profile view of the same. 
Fig. 3. 673. 1. BrONTEUS? NIAGARENSIS. (Pag. 314.) 
