96 MICROSCOPY FOR BEGINNERS. 



5. HlMANTIDIUM PECTINALE (Fig. 66). 



Frustules much wider than the preceding, transverse 

 lines distinct on both sides of a narrow central smooth 

 space (Fig. 66). 



Fig. 60. Himantidium pectinate. Fig. 67. Encyonema parad6xa. 



6. ENCYONEMA PARADOXA (Fig. 67). 



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

 branched, the frustules commonly arranged in longi- 

 tudinal lines within the tubes, which are attached to 

 other plants (Fig. 67). 



7. COCCONEMA LANCEOLATA (Figs. 68 and 68a). 

 Stems often much branched, attached to aquatic 

 plants and other submerged objects, frustules on the 

 ends of the branches, in side view (valves) slightly 

 curved with a median longitudinal line, a 

 nodule at each end and in the centre (Fig. 

 68). The frustules are often found sepa- 

 rated from the stems and floating freely, 

 when they are usually seen in side view. 

 Fig. 68# shows a single valve highly mag- 

 nified. 



8. GOMPHONEMA ACUMINATA (Fig. 69). 



Stems often much branched, but fre- 

 queiitly found uubranched ; attached to 



Cocconema * J 



lanceoiata. other plants ; frustules slightly swollen in 



