37 



12a Frustules with bulbous ends, slightly concave in girdle view, 

 typically forming stellate colonies - ASTERIONET.T.A 



Fig. hi. Asterionella formosa, (3), cells 30-l^Ou long, l-2u wide; 



free ends inflated less than joined ends. Widely distributed. 



valve view 



X 1500 



Colony 



X 500 



Notes: 



Fig. h2. Asterionella gracillima , (3), cells 40-130U long, l-2u wide; 

 similar to A. formosa except that the two poles of the cell 

 are of equal size in both valve and girdle view. 



t"inimniiiiiiiln | "i""""t""""i"' ■ l Mll ll ll llll lll' l l li ni 'l il |i|lllir i li;"Un— ^J 



valve view 

 x 1500 



Colony 



x 500 



Notes: 



