EXPLANATION OF PLATE IL 



Fig. 1. AsAPniscus Wiieeleri. (Pugo 43.) 



a. A full-sized imliviclii.il, outlines restored. 



b. Young iiijividual. 



c. Fragment, showing course of facial suture and characters of the glabella. 



d. Individual of medium size, showiug thorax aud pygidium complete. 



e. Separate thoracic segment, enlarged. 



/. Pj-gidium ; crust of broad border partly removed, showing tbo character of the striation 

 upon Its under surface. 

 Fig. 2. CoNocoRYPnE (Ptyciiopahia) Kingii. (Page 40.) 



a. Adult individual. 



h. Young individual, showing its greater proportionate size of head and length of ebcek- 

 spines. 



c. Another young individual, much enlarged, showing the faint lines passing from the fi'out 

 end of each eye to the glabella; movable cheeks separated at the facial sutures. 

 Fig. 3. Olenellus Giliserti. (Page 44.) 



0. Head, full size, broken outlines restored. 



6. Head, not full-grown. 



c. Head, young. 



(1. Lorg third pleura, with remainder of thoracic segment restored. 



e. Pleura of another segment ; missing parts restored. 

 Fig. 4. Olenellus Howelli. (Page 47.) 



a. Head, full size, fop view. 



1). The same, side view. 

 Fig. t>. Agnostus interstrictus. (Pago 38.) 



a. Top view, much enlarged. 



b. The same, side view. 



