56 Clarence J. Elmore 



Seneca, Seward, Snake River, South Bend, Stromsburg, Talmage, 

 Tekamah, Thedford, Valentine, Wann, Weeping Water, West Point, Whit- 

 man, Willow Lake, Woodlake. 



Fossil : Agate, Cherry County, Greeley County, Hay Springs, Loup 

 City, Merriman, Mullen, Spalding, Thedford, Valentine, Williams's 

 Canyon. 



Belvidere, Blackpipe, Cutmeat, Kadoka, Little White River, Norris, 

 Rapid City, Redleaf , Rosebud, Weta, S. Dak. ; Devils Lake and fresh 

 water near Devils Lake, N. Dak. ; Cheyenne, Wyo. ; Fresno, Stockton, 

 Cal.; Blackhand, Granville, New Concord, Put-in Bay, Rio Grande, Ohio. 



6. Synedra capitata Ehr. in Poggcndorff's Annalcn Phys., pi. s, 



fig. 3. 1836. 



PI. 4, fig. 140. 



Linear, 200-500 ^u, long, apices triangular-capitate, somewhat at- 

 tenuated at the tip ; pseudoraphe narrovi^ ; striations distinct, about 

 8 in 10 IX. This species seems to be somewhat constant in form, 

 but variable in size. The form called S. ulna var. longissima, figs. 

 138-139, seems to belong to this species, as all gradations are 

 found between the two. 



Tn springs, etc., with luxuriantly-growing algae and other diatoms : 

 Anselmo, Bellevue, Burge, Gordon Creek, Norfolk. North Platte, Oak- 

 dale, St. Paul, Scottsblufif, Seneca, Thedford, Valentine, Woodlake. 



Fossil : Agate, Greeley County, Loup City, Merriman, Mullen, Spalding, 

 Thedford, Valentine, Wheeler County. 



7. Synedra amphicephala Kiitz. Bacill., p. 64, pi. 3, fig. 12. 



1844. 



PI. 4, figs. 141-142, 



Very narrowly lanceolate with ends more or less rostrate-capi- 

 tate, 40-60 |U, long; striations very distinct, 11-12 in 10 /x, leaving a 

 narrow but distinct pseudoraphe. 



Atkinson. 



Fossil : Agate, Cherry Co. 



8. Synedra famelica Kiitz. BacilL, p. 64, pi. 14, fig. 8. 1844. 

 PI. 4, fig. 143. 



Broadly to narrowly lanceolate; apices rostrate-capitate. 22-30 |U 

 long; striations 20-21 in 10 /x, leaving a very narrow or indistinct 

 pseudoraphe. 



Pool by railroad. Devils Lake, N. Dak. 



