356 



TABELLARIA. 



B. More than two false septa. 



a. Fossil or fresh water forms. 



GENUS 68. TABELLARIA EHR., 1839. 



Valves inflated at the median portion and at 

 the apices, striae transverse, but without costae. 

 Girdle face showing false internal septa, gener- 

 ally alternate. Frustules united in a zig-zag 

 filament. 



Endochrome granular, with sparse granules. 



Fig. 106. 

 Tabellaria fenestrata. 



a. Valve view. 



b. Girdle view. 



ANALYSIS OF SPECIES. 

 r Median inflation much broader than the terminal ; septa numerous . T. flocculosa. 



I Median and terminal inflations equal ; two to four septa . . T. fenestrata. 



T. fenestrata (Lyng.) Kiitz. (Bac, p. 127, pi. 17, f. 22, etc. ; 



H.V.H. Atl., pi. 52, f. 6-8*; Type No. 346), plate 11, fig. 477. 



Valve linear, very elongate, strongly inflated at the median portion and at 

 the apices. Pseudo-raphe narrow, dilated at the inflations. Striae, 10 in 

 t c.d.m., finely punctate. Girdle face narrow, showing a small number 

 (generally two pairs) of false internal septa. Length, about 7 to 10 c.d.m. 



Fresh water. Rare. Antwerp, Louvain (P. Gautier). Ard. Lieg. (De Wild.), England 

 (Kitton, Comber, Brightwell, &c,), Wales, Ireland, and throughout Europe. 



