ON MERLIA NOJJMANl. 



683 



I believe the whole skeleton to be made of calcified calco- 

 cytes. Fig. 22 on El. 35 shows a camera lucida drawing by 

 Mr. Highley of a couule; which seems to :ne to be nothing 

 else than a petrified ciilcocyte. For the conule fits like a cap 

 on the rounded surface to which it is attached; also the edges 

 of its base are rounded and show a lobose process. Further, 

 there is an appearance of an oval nucleus in the interior, and 

 the fine structure shows the uranules each with the dark 

 central point. 



In the crypts and on the bars of the polygonal network the 



Text-fjg. 5. 



Flattened caleocytes on the surface of a mass of crypt tissue. 

 X 750. 



surface caleocytes are spread out in the form of plates (PI. 

 34, fig. 6, and PI. 36, fig. 1, both in vertical section), and 

 the nucleus forms a little hump-like projection on the surface 

 facing the soft tissues. 



The supposed epithelium on the surface of the masses of 

 crypt-cells is composed simply of flattened-out caleocytes of the 

 same nature as the massive cells in the interior of the mass. 

 Fig. 1 on PI. 36 is drawn from sections made from material in 

 which the fixing fluid did not well penetrate. The large nuclei 

 of the plate-like caleocytes are shrunk and compressed, and cut 

 into vertical sections. Fig. 6 on PI. 34 shows much better the 



