The Diatoms of Nebraska 45 



showing two pairs of septa extending nearly to the middle of the 

 cell. 



With Chara in creek, Grand Island. 



8. Striatella (Tabellaria) 



Striatella Ag. Consp. Diat., p. 60. 18^2. 



Etym., diminutive of Lat. stria, striations, on account of the 

 conspicuous striations. 



Tabellaria Ehr. in Ber. Berl. Akad., p. 211. 1840. 



Cells in girdle view rectangular, tabulate ; at first attached and 

 joined in bands, soon separated and united at the angles by a 

 gelatinous isthmus ; with plane dissepiments, usually alternate ; in 

 valve view cells more or less inflated at the ends and in the middle, 

 transversely striate, without costae. Endochrome granular, scat- 

 tered. Auxospores two, arising from a single mother cell. 



A. Median inflation much broader than the terminal, septa numerous. 



1. S.. flocculosa. 

 AA. Median and terminal inflations equal, septa two to tour. 



2. S. fencstrata. 



1. Striatella flocculosa (Roth) Kuntze. Rev. Gen. Plant., Ill, 2, 



p. 432. i8p8. 

 Conferva flocculosa Roth. Catal., I, p. 2^2, pi. 4, fig. 4. ijgy. 

 Tabellaria flocculosa (Roth) Kiitz. Bacill., p. 12/, pi. ly, fig. 



21. 1844. 

 PI. I, fig. 37. 



Cells linear, 20-40 /u, long, middle inflated more than the ends ; 

 striations punctate, about 13 in 10 /t, lacking in the central infla- 

 tion ; pseudoraphe narrow ; girdle face narrow, showing numerous 

 (4-8) false septa. 



Thedford. 



2. Striatella fenestrata (Kiitz.) Kuntze. Rev. Gen. Plant., Ill, 



2, p. 432. i8p8. 

 Tabellaria fenestrata Kiitz. Bacill., p. i2/, pi. ly, fig. 22. 1844. 

 PI. I, figs. 38-39. 



Cells linear, 50-100 /a long, middle and apices nearly equally 

 inflated; pseudoraphe narrow, dilated at the inflations; striations 



