PLALE II. 



Pleueoctstites filitextus (page 50). 



Figure 1« is a specimen ■which has the column and a portion of the arms iirmly attached 

 to a piece of limestone. The greater part of the body however is loose, 

 and can be removed in one piece, giving a view of the ventral side. 

 " 16 is the ventral side, shewing the large plates of the integument, and obscurely 

 the small aperture near the apex. The specimen is somewhat distorted 

 by pressure, so that the true form of the rhombs cannot be made out. 

 0, the mouth. 



Pleurocystites elegans (page 51). 



Figures 2ft, 2b, 2c, and 2d ? are dorsal views of this species. It is doubtful whether 2d, 

 should be referred to this species or to the thickly striated varieties of 

 P. filitextus. The crushed condition of this, and indeed of all the speci- 

 mens, renders it most difficult to decide when the species are so closely 

 allied. 



