The Diatoms of Nebraska 65 



PI. 6, fig. 184. 



Linear-elliptic, more or less sv/ollen in the middle and at the 

 ends, 161-300 /A long, 23-30 /x wide; costae radiating at the center 

 and converging at the ends, coarse, 5-7 in 10 /a, extending more 

 nearly to the raphe than in A'', nob His. 



With luxuriantly-growing algae in rivers, lakes, ponds, etc. : Aspinwall, 

 Clear Lake, Crawford, Dewey Lake, Dismal River, Fairbury, Grand Island, 

 Hackberry Lake, Halsey. Lakeside, Long Pine, Louisville, New Helena, Red 

 Cloud, Rupert, St. Michael, Seneca, Thedford, Wahoo. 



Fossil: Agate, Cherry County, Hay Springs, Loup City, Merriman, 

 Spalding, Thedford, Valentine. 



Rosebud, S. Dak. ; Stockton, Cal. 



3. Navicula viridis (Nitz.) Ktitz. BacilL, p. q/, pi. 4, fig. 18; 



pi. 30, fig. 12. 1844. 



Bacillaria viridis Nitz. Bcitr., pi. 6, figs. 1-3. 181/. 



PI. 6, figs. 185-191. 



Linear-elliptic, often slightly oval, without inflations; ends 

 rounded, 20-200 /^ long, 11-32/* wide; costae heavy, 5-8 in 10 /x, 

 extending nearly to the raphe, radiating in the center, converging 

 at the ends. 



In ponds, creeks, rivers, ditches, tanks, etc. : Andrews, Arago, Ashland, 

 Aspinwall, Auburn, Broken Bow, Burge, Brownlee, Cairo, Callaway 

 Central City, Clear Lake, Columbus, Crawford, Culbertson, Dewey Lake, 

 Dismal River, Dunbar, Dunning, Fairbury, Fremont. Gordon Creek, Grand 

 Island, Hackberry Lake, Halsey, Holt County, Lakeside, Lincoln, Lodi, 

 Long Pine, Louisville, Meadow, New Helena, North Platte, O'Neill, 

 Orella, Pelican Lake, Rupert, St. Michael, St. Paul, Seneca, Snake River, 

 Stanton, Stromsburg, Tekamah, Thedford, Trenton, Valentine, Wahoo,, 

 Wann, Weeping Water, West Point. 



Fossil ; Agate, Cherry County, Greeley County, Hay Springs, Loup City, 

 Merriman, Mullen, Thedford, Valentine. 



Blackpipe, Little White River, Rapid City, Rosebud, Turtle River, S. 

 Dak. ; Cheyenne, Wyo. ; Court Lake and fresh water near Devils Lake, 

 N. Dak. ; Stockton, Cal. ; Ft. Collins, Colo. 



4. Navicula lata (Breb.) Ktitz. BacilL, p. Q2, pi. 5, fig. $1. 1844. 

 Fntstulia lata Breb. Consp. Diat., p. 18. 1838. 



PI. 7, figs. 192-193. 



Linear-elliptical or elliptical, often inflated in the middle, 32- 

 iiO/x long, 14-40 yu, wide; apices obtuse, broadly rounded; costae 



