The Diatoms of Nebraska 127 



Blackpipe, Cutmeat, Little White River, Norris, Rapid City, Redleaf, 

 Rosebud, S. Dak.; Court Lake, fresh water near Devils Lake, N. Dak.; 

 Stockton, Cal. ; Blackhand, Ohio. 



2. Cystopleura sorex (Kiitz.) Kimtze. Rev. Gen. Plant., II, p. 



891. i8pi. 



Epithemia sorex Kiitz. Bacill., p. 33, pi. 5, fig. XII, 5. 1844. 



PI. 17, figs. 649-652. 



Valves strongly arcuate, 24-40 /a long, 8-10 |tA wide; ends usually 

 capitate, sometimes only slightly so ; costae distinct, radiate, 6r-y 

 in 10 jx; striations granular, 12-14 in 10 /x; cells in girdle view long- 

 oval, broadened in the middle. 



In creeks, rivers, ponds, etc., also fossil : Cedar Creek, Peru, Rulo, 

 St. Paul, Scottsblufif, Seneca, Valentine. 



Fossil : Thedford. 



Belvidere, Little White River, S. Dak.; Devils Lake, N. Dak.; Ft. Col- 

 luis, Colo. 



3. Cystopleura gibba (Ehr.) Kuntze. Rev. Gen. Plant., II, p. 



8gi. i8pi. 

 Navicida gibba Ehr. Abh. 1830. 

 Epithemia gibba (Ehr.) Kiitz. Bacill., p. 35, pi. 4, fig. 22. 



1844. 

 PI. 17, figs. 653-654. 



Linear, slightly curved, 85-200 /* long, 21-23 ;u, wide; dorsal 

 margin slightly convex, somewhat inflated in the middle; ventral 

 margin nearly straight; costae parallel, 6-8 in 10 /a; striations 

 granular, 12-14 ^^ 10 /a. 



Very common in creeks, tanks, rivers, etc., w^ith various algae or with 

 diatoms only, also fossil : Anselmo, Benkleman, Big Alkali Lake, Brownlee, 

 Burge, Central City, Clear Lake, Cody Lake, Crawford, Culbertson, Dis- 

 mal River, Dunning, Fremont, Grand Island, Hackberry Lake, Haigler, 

 Holt County, Humboldt, Ithaca, Lakeside, Long Pine, Meadow, North 

 Platte, Oakdale, Orella, Orleans, Phalaris Lake, Ruby, Rupert, Scottsblufif, 

 Seneca, St. Michael, St. Paul, Stanton, Talmage, Thedford, Valentine, 

 Wahoo, Woodlake. 



Fossil : Agate, Cherry County, Greeley County, Loup City, Merriman, 

 Mullen, Thedford, Valentine, Wheeler County. 



Belvidere, Blackpipe, Cutmeat, Dallas, Imlay, Little White River, Nor- 

 ris, Rapid Citj', Rosebud, Turtle River, S. Dak. ; Court Lake, Devils Lake, 



