The Diatoms of Nebraska 143 



Belvidere, Corn Creek, Little White River, Rapid City, Redleaf, Scenic, 

 Weta, S. Dak. ; Devils Lake and fresh water near Devils Lake, N. Dak. ; 

 Stockton, Cal. ; Blackhand, Muskingum River, Ohio. 



25. Homoeocladia frustulum (Kutz.) Kuntze. Rev. Gen. Plant., 



Ill, p. 409. i8p8. 



Nitzschia frustulum (Kiitz.) Grim, in CI. & Grim. Arct. Diat., 

 p. 98. 1880. . 



Synedra frustulum Kiitz. BacilL, p. 6j, pi. 30, fig. 77. 1844. 



PI. 20, figs. 758-760. 



Linear or ovate-lanceolate, usually attenuate, sometimes slightly 

 capitate, 18-40 /x long, 4-7/* wide; keel marginal w^ith round dots, 

 9-12 in 10 ju.; striations distinct, 20-24 in 10 /x. The form de- 

 scribed as var. pcrpusilla is found, fig. 759. 



Ponds, creeks, etc.: Burge, Dismal River, Grand Island, Lincoln. 



II. Bacillaria 



26. Homoeocladia paxillifer (Miiller) Elmore. 



Vibrio pa.viUifcr Miiller. Inf., p. ^,4, pi. y, figs. 5-7. iy86. 



Bacillaria paradoxa Gmel. in Linn. Syst. Nat., ed. 12, VI. 1788. 



Nitzschia parado.va (Gmel.) Grun. in Clcve & Grun. Arct. Diat., 

 p. 85. 1880. 



PI. 20, figs. 761-763. 



Linear, 60-1 58 /* long, 3-6 /a wide, apices attenuate, slightly ros- 

 trate; carina nearly central with 6-8 round dots in 10 /x; striations 

 17-24 in 10 /t. Cells united in a stratum and moving back and 

 forth longitudinally past one another (fig. 761). 



In fresh and brackish water : Crete, Lincoln, Louisville, North Platte. 

 Fresh water near Devils Lake, N. Dak. ; Stockton, Cal. ; Emporia, 

 Kansas. 



12. LiNEARES 



A. 8-12 faint carinal dots in 10 m; valve with slight inflection in the 



middle. 27. H. linearis. 



AA. 5-7 distinct carinal dots in 10 m; no median inflection. 



28. H. vitrca. 



27. Homoeocladia linearis (Ag.) Kuntze. Rev. Gen. Plant., Ill, 



p. 4op. i8p8. 

 Nitzschia linearis (Ag.) W. Sm. Brit. Diat., I, p. sp, pi. 15, 

 fig. no. 1853. 



