The Diatoms of Nebraska 141 



5-8 in 10 fi, the middle ones not separated more than the others; 

 striations 24-30 in 10 jx. 



Grand Island, Valentine. 



Devils Lake, N. Dak. ; Emporia, Kansas. 



21. Homoeocladia subtilis (Grun.) Kuntze. Rev. Gen. Plant., 



Ill, p. 40p. i8p8. 



Nitsschia subtilis Grun. in CI. & Grun. Arct. Diat., p. 95. 1880. 



PI. 20, fig. 740. 



Narrowly lanceolate, 49-120 /a long, 4.5-9 ju. wide, apices at- 

 tenuate; keel marginal with dots not elongated, 7-13 in 10 ju,, the 

 two middle dots more distant than the rest ; striations 30-32 in 

 10 /a; girdle face straight. The form described as var. palcacea is 

 smaller and more delicate with 12-14 dots in \o fx. 



In creeks, ponds, pools, etc. : Arago, Brock, Grand Island, Humboldt, 

 Johnson, Julian, Lincoln, Louisville, Oakdale, Orleans, Peru, Pleasant 

 Dale, Seneca, Talmage, Weeping Water. 



Kadoka, S. Dak. ; Put-in Bay, Ohio. 



22. Homoeocladia intermedia (Hantz.) Kuntze. Rev. Gen. 



Plant., Ill, p. 40p. i8p8. 

 Nitsschia intermedia Hantz. in CI. & Grim. Arct. Diat., p. pj. 



1880. 

 PI. 20, figs. 741-742. 



Linear, slightly lanceolate, 68-100 /x, long, apices attenuate, 

 slightly rostrate; keel somewhat excentric with 8-9 dots in 10 /a; 

 striations about 24 in 10 /x. 



With Oscillatoria in springs, marshes, watering troughs, stagnant pools, 

 etc. : Dawson, Long Pine, Peru, Salem. 

 Fossil : Loup City. 



23. Homoeocladia amphibia (Grun.) Kuntze. Rev. Gen. Plant., 



Ill, p. 408. i8p8. 



Nitzschia amphibia Grun. in IVicn. Verh., p. ^74. 1862. 



PI. 20, figs. 743-751- 



Linear or ovate-lanceolate, usually attenuate, apices usually 

 rounded, sometimes slightly capitate, 14-60 ;«, long, 3.3-8/1. wide; 

 keel marginal with round dots, 6-8 in lO/^; striations distinct, 

 12-17 i'^ 10 A^; cells sometimes united in bands like FragUaria. 



