DESMIDS, DIATOMS, AND FRESH-WATER ALGiE. 93 



Fig. 65^ the appearance of a single valve more highly- 

 magnified. The ends of the valves are somewhat 

 wedge-shaped. 



5 HiMANTfDIUM pectinAle (Fig. 66). 



Frustules much wider than the preceding; transverse 

 B lines distinct on both sides 

 of a narrow central smooth 

 space (Fig. 66). A is the 

 side view of a single frus- 



Fig. 66. — Himantidium pectin^le. 



6 Encyon£ma parad6xum (Fig. 67). 



The jelly-tubes are usually very slightly, if at all, 

 branched, the frustules commonly arranged in a longi- 

 . ■ tudinal series with- 

 in the tubes, which 

 are attached to 

 qther plants (Fig. 

 67). 



Fig. 67. — Encyonema parad6xum. 



7 CoccoNEMA lanceolAtum (Figs. 68 and 



JFies. 68 and 68a.- 



Coccon^ma lan- 



ceoldtum. 



Stems often much branched; at- 

 tached to aquatic plants and to other 

 submerged objects; frustules on the 

 ends of the branches, in side view 

 (valves) slightly curved, with a median 

 longitudinal line having a nodule at 

 each end and one in the center (Fig. 

 68). The frustules ,ai:e • often found 

 floating freely, when they are usually 

 seen in side view. Fig. 68« shows a 

 single valve highly magnified. 



