PLATE VI. 



Amtgdalocystites floeealis (page 63). 



Figure la. The left side of a specimen; m, the mouth. 



" \h. Right side of the same. 



" Ic. Posterior view. 



" Id. Anterior views. The groove is not clearly shown in this specimen. 



" le. One of the plates enlarged. 



Amtgdalocystites tenuisteiatus (page 64). 



Figures 2a, 26. Right and left side of the Ottawa specimen; m, the mouth. 



" 2c. Left side of a specimen from Belleville, shewing a portion of the arm. 



" 2e. The arm enlarged, shewing the ambulacral groove. 



" 2/. View of the top of the arm, shewing the articulating cavities of the pin- 



nulasi and the branches of the ambulacral grooves leading to them. 

 " 2d. A plate enlarged, shewing the striae. 



Amygdalocystites radiatus (page 65). 



Figure 3a. A specimen crushed fiat, imbedded in stone. 



" 3&. One of the plates enlarged. The specimen is worn, and does not shew the 

 granular surface of the spaces between the radiating ridges. 



