LICMOPHORA. 



34' 



Fig. 98. Gephyria media. 



Tribe XIL LicmophorEvE. 



f Frustules cuneate, showing on the valve face a single vitta rounded, and 



more or less approximate to the enlarged apex . . . Licmophora. 



Frustules cune.Ue, showing on the valve face a large number of transverse 

 septa, simulating the steps of a ladder (scalariform) . . . Climacosphenia. 



GENUS 61. LICMOPHORA (AGARDH), 1827. 



Valves more or less cuneate, with monili- 

 form striae, pseudo-raphe conspicuous. Frus- 

 tules cuneate, showing internal septa. Endo- 



chrome granular, sparse on the internal sur- 



5 face of the frustules. 



The genus Licmophora, as it exists at the 

 present time, results from the fusion of the three 

 former genera Licmophora, Podosphenia and Rhipi- 

 dophora, founded on inadmissible differences, and 

 which Kvitzing based on the comparative breadth 

 of the valve and the presence or the absence of a 

 stipes. 



About thirty Licmophora have been described, the larger number of these 

 forms presenting only the smallest differences, and many given as species 

 ought to be placed in the rank of varieties only. 



Fig. 99. 

 Licmophora Californica. 



