TEANSVERSE SECTIONS 25 



lamella. The nucleus is usually nearer the outer or 

 basal end, and is fattened in shape. The £agella 

 can very seldom be seen in sections. 



In the foot the endoderm cells are much smaller 

 than in the body, and form a row of short columnar 

 or almost cubical cells containing granular concre- 

 tions. 



