Fig. C. 



Eupledella aspergillum. a. Section of a lidge and part of wall x 15. a. dermal 

 layer; 6, flagellated chambers; c, gastral cavity ; (?, bandies of sword-shaped 

 spicules each tipped with a ttoricome. b. Regular six-rayed spicule X 100. 

 c. Flori«omc spicule x 300. (After F. P]. Schulze.) 



To face p. 26. 



