144 



Clarence J. Elmore 



Frustulia linearis Ag. "ex spec, aufhen. quae misit Dr. Gre- 

 ville," W. Sm., I.e. 



PI. 20, figs. 764-765 ; pi- 23, fig- 859. 



Linear, 70-180 /a long, 5-6 /x wide, sometimes with a constriction 

 in the middle, apices attenuate, rostrate or capitate ; keel somewhat 

 excentric with 8-12 dots in lO/x; striations indistinct, 22-24 in 

 10 /A. The form represented by var. tenuis, fig. 765, resembles the 

 type, but is smaller and has finer striations, about 30 in 10 lu.. 



In creeks with Oscillatoria, Spirogyra, Vaucheria, etc. : Andrews, Fair- 

 bury, Grand Island, Humboldt, Lincoln, Talmage, Wahoo, Weeping Water. 

 Fresno, Cal. 



28. Homoeocladia vitrea (Norm.) Kuntze. Rev. Gen. Plant., 



Ill, p. 4op. i8g8. 



Nitzschia vitrea Norm, in Jour. Mic. Soc, IX, p. 7. 1861. 



PI. 20, figs. 76^-768. 



Linear-lanceolate, often tapering more on one margin than the 

 other, 50-130^ long; keel somewhat excentric with large sqtiare 

 or roimded dots, 5-8 in 10 /x; striations 20-22 in 10 /a. The form 

 described as var. recta is smaller and more linear with more 

 rounded apices and finer striations, fig. 768. 



In creeks and ponds with Spirogyra or Hormiscia: Arago, Auburn, Fair- 

 bury, Orella, Peru, Scottsbluff, Talmage, Whitman. 

 Fresh water near Devils Lake, N. Dak. 



13. DiSSIPATAE 



29. Homoeocladia dissipata (Kutz.) Kuntze. Rev. Gen. Plant., 



Ill, p. 4op. 1898. 

 Nitsschia dissipata (Kiitz.) Grun. in CI. & Grun. Arct. Diat., 



p. po. 1880. 

 Synedra dissipata Kiitz. BacilL, p. 64, pi. 14, fig. 3. 1844. 

 PI. 20, figs. 769-771. 



Lanceolate, 20-45 /^ long, about 5 fx wide, apices attenuate, 

 slightly rostrate; keel somewhat excentric with 6-8 dots in 10 /x; 

 striations not distinct. Van Heurck. Diat., p. 3Q4, quotes Kitton 

 as authority for there being 14 in 10 ix. 



In creek, Long Pine. 



