1? 



49. Tr\ l)lioiH'lla : (gracilis). 



r^uilllUIHIHIIIIIIIIHHIIIIIIilJTn? 



^LXlMliHlllllllllllUIIIIIIIHIiniii^ 



a) Frustula a fronte visa, b) a latere ; transverse striata, carina margini 

 altero approximata instructa; punctis vel costis carinalibus obsoletis. 



K. ■ inlividiia in fascias taliiilatas coiijimcta. 



50. Bacillaria: (paradoxa). 



Frustula illis Nitzschiae similia. 



€'. Indivitlua gclatina tuliulosa \el mciii- 

 brauacea iuclusa. 



51. Homoeocladia: 



Frustula ut in Nitzschia, sed tubo gelineo inclusa. 



Kabenhorst, Flora Europaea 2 . 



